1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2015, 2016 The FreeBSD Foundation
5 * Copyright (c) 2004, David Xu <davidxu@freebsd.org>
6 * Copyright (c) 2002, Jeffrey Roberson <jeff@freebsd.org>
7 * All rights reserved.
8 *
9 * Portions of this software were developed by Konstantin Belousov
10 * under sponsorship from the FreeBSD Foundation.
11 *
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
14 * are met:
15 * 1. Redistributions of source code must retain the above copyright
16 * notice unmodified, this list of conditions, and the following
17 * disclaimer.
18 * 2. Redistributions in binary form must reproduce the above copyright
19 * notice, this list of conditions and the following disclaimer in the
20 * documentation and/or other materials provided with the distribution.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
23 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
24 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
25 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
26 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
27 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
28 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
29 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
30 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
31 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32 */
33
34 #include <sys/cdefs.h>
35 #include "opt_umtx_profiling.h"
36
37 #include <sys/param.h>
38 #include <sys/kernel.h>
39 #include <sys/fcntl.h>
40 #include <sys/file.h>
41 #include <sys/filedesc.h>
42 #include <sys/limits.h>
43 #include <sys/lock.h>
44 #include <sys/malloc.h>
45 #include <sys/mman.h>
46 #include <sys/mutex.h>
47 #include <sys/priv.h>
48 #include <sys/proc.h>
49 #include <sys/resource.h>
50 #include <sys/resourcevar.h>
51 #include <sys/rwlock.h>
52 #include <sys/sbuf.h>
53 #include <sys/sched.h>
54 #include <sys/smp.h>
55 #include <sys/sysctl.h>
56 #include <sys/systm.h>
57 #include <sys/sysproto.h>
58 #include <sys/syscallsubr.h>
59 #include <sys/taskqueue.h>
60 #include <sys/time.h>
61 #include <sys/eventhandler.h>
62 #include <sys/umtx.h>
63 #include <sys/umtxvar.h>
64
65 #include <security/mac/mac_framework.h>
66
67 #include <vm/vm.h>
68 #include <vm/vm_param.h>
69 #include <vm/pmap.h>
70 #include <vm/uma.h>
71 #include <vm/vm_map.h>
72 #include <vm/vm_object.h>
73
74 #include <machine/atomic.h>
75 #include <machine/cpu.h>
76
77 #include <compat/freebsd32/freebsd32.h>
78 #ifdef COMPAT_FREEBSD32
79 #include <compat/freebsd32/freebsd32_proto.h>
80 #endif
81
82 #define _UMUTEX_TRY 1
83 #define _UMUTEX_WAIT 2
84
85 #ifdef UMTX_PROFILING
86 #define UPROF_PERC_BIGGER(w, f, sw, sf) \
87 (((w) > (sw)) || ((w) == (sw) && (f) > (sf)))
88 #endif
89
90 #define UMTXQ_LOCKED_ASSERT(uc) mtx_assert(&(uc)->uc_lock, MA_OWNED)
91 #ifdef INVARIANTS
92 #define UMTXQ_ASSERT_LOCKED_BUSY(key) do { \
93 struct umtxq_chain *uc; \
94 \
95 uc = umtxq_getchain(key); \
96 mtx_assert(&uc->uc_lock, MA_OWNED); \
97 KASSERT(uc->uc_busy != 0, ("umtx chain is not busy")); \
98 } while (0)
99 #else
100 #define UMTXQ_ASSERT_LOCKED_BUSY(key) do {} while (0)
101 #endif
102
103 /*
104 * Don't propagate time-sharing priority, there is a security reason,
105 * a user can simply introduce PI-mutex, let thread A lock the mutex,
106 * and let another thread B block on the mutex, because B is
107 * sleeping, its priority will be boosted, this causes A's priority to
108 * be boosted via priority propagating too and will never be lowered even
109 * if it is using 100%CPU, this is unfair to other processes.
110 */
111
112 #define UPRI(td) (((td)->td_user_pri >= PRI_MIN_TIMESHARE &&\
113 (td)->td_user_pri <= PRI_MAX_TIMESHARE) ?\
114 PRI_MAX_TIMESHARE : (td)->td_user_pri)
115
116 #define GOLDEN_RATIO_PRIME 2654404609U
117 #ifndef UMTX_CHAINS
118 #define UMTX_CHAINS 512
119 #endif
120 #define UMTX_SHIFTS (__WORD_BIT - 9)
121
122 #define GET_SHARE(flags) \
123 (((flags) & USYNC_PROCESS_SHARED) == 0 ? THREAD_SHARE : PROCESS_SHARE)
124
125 #define BUSY_SPINS 200
126
127 struct umtx_copyops {
128 int (*copyin_timeout)(const void *uaddr, struct timespec *tsp);
129 int (*copyin_umtx_time)(const void *uaddr, size_t size,
130 struct _umtx_time *tp);
131 int (*copyin_robust_lists)(const void *uaddr, size_t size,
132 struct umtx_robust_lists_params *rbp);
133 int (*copyout_timeout)(void *uaddr, size_t size,
134 struct timespec *tsp);
135 const size_t timespec_sz;
136 const size_t umtx_time_sz;
137 const bool compat32;
138 };
139
140 _Static_assert(sizeof(struct umutex) == sizeof(struct umutex32), "umutex32");
141 _Static_assert(__offsetof(struct umutex, m_spare[0]) ==
142 __offsetof(struct umutex32, m_spare[0]), "m_spare32");
143
144 int umtx_shm_vnobj_persistent = 0;
145 SYSCTL_INT(_kern_ipc, OID_AUTO, umtx_vnode_persistent, CTLFLAG_RWTUN,
146 &umtx_shm_vnobj_persistent, 0,
147 "False forces destruction of umtx attached to file, on last close");
148 static int umtx_max_rb = 1000;
149 SYSCTL_INT(_kern_ipc, OID_AUTO, umtx_max_robust, CTLFLAG_RWTUN,
150 &umtx_max_rb, 0,
151 "Maximum number of robust mutexes allowed for each thread");
152
153 static uma_zone_t umtx_pi_zone;
154 static struct umtxq_chain umtxq_chains[2][UMTX_CHAINS];
155 static MALLOC_DEFINE(M_UMTX, "umtx", "UMTX queue memory");
156 static int umtx_pi_allocated;
157
158 static SYSCTL_NODE(_debug, OID_AUTO, umtx, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
159 "umtx debug");
160 SYSCTL_INT(_debug_umtx, OID_AUTO, umtx_pi_allocated, CTLFLAG_RD,
161 &umtx_pi_allocated, 0, "Allocated umtx_pi");
162 static int umtx_verbose_rb = 1;
163 SYSCTL_INT(_debug_umtx, OID_AUTO, robust_faults_verbose, CTLFLAG_RWTUN,
164 &umtx_verbose_rb, 0,
165 "");
166
167 #ifdef UMTX_PROFILING
168 static long max_length;
169 SYSCTL_LONG(_debug_umtx, OID_AUTO, max_length, CTLFLAG_RD, &max_length, 0, "max_length");
170 static SYSCTL_NODE(_debug_umtx, OID_AUTO, chains, CTLFLAG_RD | CTLFLAG_MPSAFE, 0,
171 "umtx chain stats");
172 #endif
173
174 static inline void umtx_abs_timeout_init2(struct umtx_abs_timeout *timo,
175 const struct _umtx_time *umtxtime);
176
177 static void umtx_shm_init(void);
178 static void umtxq_sysinit(void *);
179 static void umtxq_hash(struct umtx_key *key);
180 static int do_unlock_pp(struct thread *td, struct umutex *m, uint32_t flags,
181 bool rb);
182 static void umtx_thread_cleanup(struct thread *td);
183 SYSINIT(umtx, SI_SUB_EVENTHANDLER+1, SI_ORDER_MIDDLE, umtxq_sysinit, NULL);
184
185 #define umtxq_signal(key, nwake) umtxq_signal_queue((key), (nwake), UMTX_SHARED_QUEUE)
186
187 static struct mtx umtx_lock;
188
189 #ifdef UMTX_PROFILING
190 static void
umtx_init_profiling(void)191 umtx_init_profiling(void)
192 {
193 struct sysctl_oid *chain_oid;
194 char chain_name[10];
195 int i;
196
197 for (i = 0; i < UMTX_CHAINS; ++i) {
198 snprintf(chain_name, sizeof(chain_name), "%d", i);
199 chain_oid = SYSCTL_ADD_NODE(NULL,
200 SYSCTL_STATIC_CHILDREN(_debug_umtx_chains), OID_AUTO,
201 chain_name, CTLFLAG_RD | CTLFLAG_MPSAFE, NULL,
202 "umtx hash stats");
203 SYSCTL_ADD_INT(NULL, SYSCTL_CHILDREN(chain_oid), OID_AUTO,
204 "max_length0", CTLFLAG_RD, &umtxq_chains[0][i].max_length, 0, NULL);
205 SYSCTL_ADD_INT(NULL, SYSCTL_CHILDREN(chain_oid), OID_AUTO,
206 "max_length1", CTLFLAG_RD, &umtxq_chains[1][i].max_length, 0, NULL);
207 }
208 }
209
210 static int
sysctl_debug_umtx_chains_peaks(SYSCTL_HANDLER_ARGS)211 sysctl_debug_umtx_chains_peaks(SYSCTL_HANDLER_ARGS)
212 {
213 char buf[512];
214 struct sbuf sb;
215 struct umtxq_chain *uc;
216 u_int fract, i, j, tot, whole;
217 u_int sf0, sf1, sf2, sf3, sf4;
218 u_int si0, si1, si2, si3, si4;
219 u_int sw0, sw1, sw2, sw3, sw4;
220
221 sbuf_new(&sb, buf, sizeof(buf), SBUF_FIXEDLEN);
222 for (i = 0; i < 2; i++) {
223 tot = 0;
224 for (j = 0; j < UMTX_CHAINS; ++j) {
225 uc = &umtxq_chains[i][j];
226 mtx_lock(&uc->uc_lock);
227 tot += uc->max_length;
228 mtx_unlock(&uc->uc_lock);
229 }
230 if (tot == 0)
231 sbuf_printf(&sb, "%u) Empty ", i);
232 else {
233 sf0 = sf1 = sf2 = sf3 = sf4 = 0;
234 si0 = si1 = si2 = si3 = si4 = 0;
235 sw0 = sw1 = sw2 = sw3 = sw4 = 0;
236 for (j = 0; j < UMTX_CHAINS; j++) {
237 uc = &umtxq_chains[i][j];
238 mtx_lock(&uc->uc_lock);
239 whole = uc->max_length * 100;
240 mtx_unlock(&uc->uc_lock);
241 fract = (whole % tot) * 100;
242 if (UPROF_PERC_BIGGER(whole, fract, sw0, sf0)) {
243 sf0 = fract;
244 si0 = j;
245 sw0 = whole;
246 } else if (UPROF_PERC_BIGGER(whole, fract, sw1,
247 sf1)) {
248 sf1 = fract;
249 si1 = j;
250 sw1 = whole;
251 } else if (UPROF_PERC_BIGGER(whole, fract, sw2,
252 sf2)) {
253 sf2 = fract;
254 si2 = j;
255 sw2 = whole;
256 } else if (UPROF_PERC_BIGGER(whole, fract, sw3,
257 sf3)) {
258 sf3 = fract;
259 si3 = j;
260 sw3 = whole;
261 } else if (UPROF_PERC_BIGGER(whole, fract, sw4,
262 sf4)) {
263 sf4 = fract;
264 si4 = j;
265 sw4 = whole;
266 }
267 }
268 sbuf_printf(&sb, "queue %u:\n", i);
269 sbuf_printf(&sb, "1st: %u.%u%% idx: %u\n", sw0 / tot,
270 sf0 / tot, si0);
271 sbuf_printf(&sb, "2nd: %u.%u%% idx: %u\n", sw1 / tot,
272 sf1 / tot, si1);
273 sbuf_printf(&sb, "3rd: %u.%u%% idx: %u\n", sw2 / tot,
274 sf2 / tot, si2);
275 sbuf_printf(&sb, "4th: %u.%u%% idx: %u\n", sw3 / tot,
276 sf3 / tot, si3);
277 sbuf_printf(&sb, "5th: %u.%u%% idx: %u\n", sw4 / tot,
278 sf4 / tot, si4);
279 }
280 }
281 sbuf_trim(&sb);
282 sbuf_finish(&sb);
283 sysctl_handle_string(oidp, sbuf_data(&sb), sbuf_len(&sb), req);
284 sbuf_delete(&sb);
285 return (0);
286 }
287
288 static int
sysctl_debug_umtx_chains_clear(SYSCTL_HANDLER_ARGS)289 sysctl_debug_umtx_chains_clear(SYSCTL_HANDLER_ARGS)
290 {
291 struct umtxq_chain *uc;
292 u_int i, j;
293 int clear, error;
294
295 clear = 0;
296 error = sysctl_handle_int(oidp, &clear, 0, req);
297 if (error != 0 || req->newptr == NULL)
298 return (error);
299
300 if (clear != 0) {
301 for (i = 0; i < 2; ++i) {
302 for (j = 0; j < UMTX_CHAINS; ++j) {
303 uc = &umtxq_chains[i][j];
304 mtx_lock(&uc->uc_lock);
305 uc->length = 0;
306 uc->max_length = 0;
307 mtx_unlock(&uc->uc_lock);
308 }
309 }
310 }
311 return (0);
312 }
313
314 SYSCTL_PROC(_debug_umtx_chains, OID_AUTO, clear,
315 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 0,
316 sysctl_debug_umtx_chains_clear, "I",
317 "Clear umtx chains statistics");
318 SYSCTL_PROC(_debug_umtx_chains, OID_AUTO, peaks,
319 CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE, 0, 0,
320 sysctl_debug_umtx_chains_peaks, "A",
321 "Highest peaks in chains max length");
322 #endif
323
324 static void
umtxq_sysinit(void * arg __unused)325 umtxq_sysinit(void *arg __unused)
326 {
327 int i, j;
328
329 umtx_pi_zone = uma_zcreate("umtx pi", sizeof(struct umtx_pi),
330 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
331 for (i = 0; i < 2; ++i) {
332 for (j = 0; j < UMTX_CHAINS; ++j) {
333 mtx_init(&umtxq_chains[i][j].uc_lock, "umtxql", NULL,
334 MTX_DEF | MTX_DUPOK);
335 LIST_INIT(&umtxq_chains[i][j].uc_queue[0]);
336 LIST_INIT(&umtxq_chains[i][j].uc_queue[1]);
337 LIST_INIT(&umtxq_chains[i][j].uc_spare_queue);
338 TAILQ_INIT(&umtxq_chains[i][j].uc_pi_list);
339 umtxq_chains[i][j].uc_busy = 0;
340 umtxq_chains[i][j].uc_waiters = 0;
341 #ifdef UMTX_PROFILING
342 umtxq_chains[i][j].length = 0;
343 umtxq_chains[i][j].max_length = 0;
344 #endif
345 }
346 }
347 #ifdef UMTX_PROFILING
348 umtx_init_profiling();
349 #endif
350 mtx_init(&umtx_lock, "umtx lock", NULL, MTX_DEF);
351 umtx_shm_init();
352 }
353
354 struct umtx_q *
umtxq_alloc(void)355 umtxq_alloc(void)
356 {
357 struct umtx_q *uq;
358
359 uq = malloc(sizeof(struct umtx_q), M_UMTX, M_WAITOK | M_ZERO);
360 uq->uq_spare_queue = malloc(sizeof(struct umtxq_queue), M_UMTX,
361 M_WAITOK | M_ZERO);
362 TAILQ_INIT(&uq->uq_spare_queue->head);
363 TAILQ_INIT(&uq->uq_pi_contested);
364 uq->uq_inherited_pri = PRI_MAX;
365 return (uq);
366 }
367
368 void
umtxq_free(struct umtx_q * uq)369 umtxq_free(struct umtx_q *uq)
370 {
371
372 MPASS(uq->uq_spare_queue != NULL);
373 free(uq->uq_spare_queue, M_UMTX);
374 free(uq, M_UMTX);
375 }
376
377 static inline void
umtxq_hash(struct umtx_key * key)378 umtxq_hash(struct umtx_key *key)
379 {
380 unsigned n;
381
382 n = (uintptr_t)key->info.both.a + key->info.both.b;
383 key->hash = ((n * GOLDEN_RATIO_PRIME) >> UMTX_SHIFTS) % UMTX_CHAINS;
384 }
385
386 struct umtxq_chain *
umtxq_getchain(struct umtx_key * key)387 umtxq_getchain(struct umtx_key *key)
388 {
389
390 if (key->type <= TYPE_SEM)
391 return (&umtxq_chains[1][key->hash]);
392 return (&umtxq_chains[0][key->hash]);
393 }
394
395 /*
396 * Set chain to busy state when following operation
397 * may be blocked (kernel mutex can not be used).
398 */
399 void
umtxq_busy(struct umtx_key * key)400 umtxq_busy(struct umtx_key *key)
401 {
402 struct umtxq_chain *uc;
403
404 uc = umtxq_getchain(key);
405 mtx_assert(&uc->uc_lock, MA_OWNED);
406 if (uc->uc_busy) {
407 #ifdef SMP
408 if (smp_cpus > 1) {
409 int count = BUSY_SPINS;
410 if (count > 0) {
411 umtxq_unlock(key);
412 while (uc->uc_busy && --count > 0)
413 cpu_spinwait();
414 umtxq_lock(key);
415 }
416 }
417 #endif
418 while (uc->uc_busy) {
419 uc->uc_waiters++;
420 msleep(uc, &uc->uc_lock, 0, "umtxqb", 0);
421 uc->uc_waiters--;
422 }
423 }
424 uc->uc_busy = 1;
425 }
426
427 /*
428 * Unbusy a chain.
429 */
430 void
umtxq_unbusy(struct umtx_key * key)431 umtxq_unbusy(struct umtx_key *key)
432 {
433 struct umtxq_chain *uc;
434
435 uc = umtxq_getchain(key);
436 mtx_assert(&uc->uc_lock, MA_OWNED);
437 KASSERT(uc->uc_busy != 0, ("not busy"));
438 uc->uc_busy = 0;
439 if (uc->uc_waiters)
440 wakeup_one(uc);
441 }
442
443 void
umtxq_unbusy_unlocked(struct umtx_key * key)444 umtxq_unbusy_unlocked(struct umtx_key *key)
445 {
446
447 umtxq_lock(key);
448 umtxq_unbusy(key);
449 umtxq_unlock(key);
450 }
451
452 static struct umtxq_queue *
umtxq_queue_lookup(struct umtx_key * key,int q)453 umtxq_queue_lookup(struct umtx_key *key, int q)
454 {
455 struct umtxq_queue *uh;
456 struct umtxq_chain *uc;
457
458 uc = umtxq_getchain(key);
459 UMTXQ_LOCKED_ASSERT(uc);
460 LIST_FOREACH(uh, &uc->uc_queue[q], link) {
461 if (umtx_key_match(&uh->key, key))
462 return (uh);
463 }
464
465 return (NULL);
466 }
467
468 void
umtxq_insert_queue(struct umtx_q * uq,int q)469 umtxq_insert_queue(struct umtx_q *uq, int q)
470 {
471 struct umtxq_queue *uh;
472 struct umtxq_chain *uc;
473
474 uc = umtxq_getchain(&uq->uq_key);
475 UMTXQ_LOCKED_ASSERT(uc);
476 KASSERT((uq->uq_flags & UQF_UMTXQ) == 0, ("umtx_q is already on queue"));
477 uh = umtxq_queue_lookup(&uq->uq_key, q);
478 if (uh != NULL) {
479 LIST_INSERT_HEAD(&uc->uc_spare_queue, uq->uq_spare_queue, link);
480 } else {
481 uh = uq->uq_spare_queue;
482 uh->key = uq->uq_key;
483 LIST_INSERT_HEAD(&uc->uc_queue[q], uh, link);
484 #ifdef UMTX_PROFILING
485 uc->length++;
486 if (uc->length > uc->max_length) {
487 uc->max_length = uc->length;
488 if (uc->max_length > max_length)
489 max_length = uc->max_length;
490 }
491 #endif
492 }
493 uq->uq_spare_queue = NULL;
494
495 TAILQ_INSERT_TAIL(&uh->head, uq, uq_link);
496 uh->length++;
497 uq->uq_flags |= UQF_UMTXQ;
498 uq->uq_cur_queue = uh;
499 return;
500 }
501
502 void
umtxq_remove_queue(struct umtx_q * uq,int q)503 umtxq_remove_queue(struct umtx_q *uq, int q)
504 {
505 struct umtxq_chain *uc;
506 struct umtxq_queue *uh;
507
508 uc = umtxq_getchain(&uq->uq_key);
509 UMTXQ_LOCKED_ASSERT(uc);
510 if (uq->uq_flags & UQF_UMTXQ) {
511 uh = uq->uq_cur_queue;
512 TAILQ_REMOVE(&uh->head, uq, uq_link);
513 uh->length--;
514 uq->uq_flags &= ~UQF_UMTXQ;
515 if (TAILQ_EMPTY(&uh->head)) {
516 KASSERT(uh->length == 0,
517 ("inconsistent umtxq_queue length"));
518 #ifdef UMTX_PROFILING
519 uc->length--;
520 #endif
521 LIST_REMOVE(uh, link);
522 } else {
523 uh = LIST_FIRST(&uc->uc_spare_queue);
524 KASSERT(uh != NULL, ("uc_spare_queue is empty"));
525 LIST_REMOVE(uh, link);
526 }
527 uq->uq_spare_queue = uh;
528 uq->uq_cur_queue = NULL;
529 }
530 }
531
532 /*
533 * Check if there are multiple waiters
534 */
535 int
umtxq_count(struct umtx_key * key)536 umtxq_count(struct umtx_key *key)
537 {
538 struct umtxq_queue *uh;
539
540 UMTXQ_LOCKED_ASSERT(umtxq_getchain(key));
541 uh = umtxq_queue_lookup(key, UMTX_SHARED_QUEUE);
542 if (uh != NULL)
543 return (uh->length);
544 return (0);
545 }
546
547 /*
548 * Check if there are multiple PI waiters and returns first
549 * waiter.
550 */
551 static int
umtxq_count_pi(struct umtx_key * key,struct umtx_q ** first)552 umtxq_count_pi(struct umtx_key *key, struct umtx_q **first)
553 {
554 struct umtxq_queue *uh;
555
556 *first = NULL;
557 UMTXQ_LOCKED_ASSERT(umtxq_getchain(key));
558 uh = umtxq_queue_lookup(key, UMTX_SHARED_QUEUE);
559 if (uh != NULL) {
560 *first = TAILQ_FIRST(&uh->head);
561 return (uh->length);
562 }
563 return (0);
564 }
565
566 /*
567 * Wake up threads waiting on an userland object by a bit mask.
568 */
569 int
umtxq_signal_mask(struct umtx_key * key,int n_wake,u_int bitset)570 umtxq_signal_mask(struct umtx_key *key, int n_wake, u_int bitset)
571 {
572 struct umtxq_queue *uh;
573 struct umtx_q *uq, *uq_temp;
574 int ret;
575
576 ret = 0;
577 UMTXQ_LOCKED_ASSERT(umtxq_getchain(key));
578 uh = umtxq_queue_lookup(key, UMTX_SHARED_QUEUE);
579 if (uh == NULL)
580 return (0);
581 TAILQ_FOREACH_SAFE(uq, &uh->head, uq_link, uq_temp) {
582 if ((uq->uq_bitset & bitset) == 0)
583 continue;
584 umtxq_remove_queue(uq, UMTX_SHARED_QUEUE);
585 wakeup_one(uq);
586 if (++ret >= n_wake)
587 break;
588 }
589 return (ret);
590 }
591
592 /*
593 * Wake up threads waiting on an userland object.
594 */
595
596 static int
umtxq_signal_queue(struct umtx_key * key,int n_wake,int q)597 umtxq_signal_queue(struct umtx_key *key, int n_wake, int q)
598 {
599 struct umtxq_queue *uh;
600 struct umtx_q *uq;
601 int ret;
602
603 ret = 0;
604 UMTXQ_LOCKED_ASSERT(umtxq_getchain(key));
605 uh = umtxq_queue_lookup(key, q);
606 if (uh != NULL) {
607 while ((uq = TAILQ_FIRST(&uh->head)) != NULL) {
608 umtxq_remove_queue(uq, q);
609 wakeup(uq);
610 if (++ret >= n_wake)
611 return (ret);
612 }
613 }
614 return (ret);
615 }
616
617 /*
618 * Wake up specified thread.
619 */
620 static inline void
umtxq_signal_thread(struct umtx_q * uq)621 umtxq_signal_thread(struct umtx_q *uq)
622 {
623
624 UMTXQ_LOCKED_ASSERT(umtxq_getchain(&uq->uq_key));
625 umtxq_remove(uq);
626 wakeup(uq);
627 }
628
629 /*
630 * Wake up a maximum of n_wake threads that are waiting on an userland
631 * object identified by key. The remaining threads are removed from queue
632 * identified by key and added to the queue identified by key2 (requeued).
633 * The n_requeue specifies an upper limit on the number of threads that
634 * are requeued to the second queue.
635 */
636 int
umtxq_requeue(struct umtx_key * key,int n_wake,struct umtx_key * key2,int n_requeue)637 umtxq_requeue(struct umtx_key *key, int n_wake, struct umtx_key *key2,
638 int n_requeue)
639 {
640 struct umtxq_queue *uh;
641 struct umtx_q *uq, *uq_temp;
642 int ret;
643
644 ret = 0;
645 UMTXQ_LOCKED_ASSERT(umtxq_getchain(key));
646 UMTXQ_LOCKED_ASSERT(umtxq_getchain(key2));
647 uh = umtxq_queue_lookup(key, UMTX_SHARED_QUEUE);
648 if (uh == NULL)
649 return (0);
650 TAILQ_FOREACH_SAFE(uq, &uh->head, uq_link, uq_temp) {
651 if (++ret <= n_wake) {
652 umtxq_remove(uq);
653 wakeup_one(uq);
654 } else {
655 umtxq_remove(uq);
656 uq->uq_key = *key2;
657 umtxq_insert(uq);
658 if (ret - n_wake == n_requeue)
659 break;
660 }
661 }
662 return (ret);
663 }
664
665 static inline int
tstohz(const struct timespec * tsp)666 tstohz(const struct timespec *tsp)
667 {
668 struct timeval tv;
669
670 TIMESPEC_TO_TIMEVAL(&tv, tsp);
671 return tvtohz(&tv);
672 }
673
674 void
umtx_abs_timeout_init(struct umtx_abs_timeout * timo,int clockid,int absolute,const struct timespec * timeout)675 umtx_abs_timeout_init(struct umtx_abs_timeout *timo, int clockid,
676 int absolute, const struct timespec *timeout)
677 {
678
679 timo->clockid = clockid;
680 if (!absolute) {
681 timo->is_abs_real = false;
682 kern_clock_gettime(curthread, timo->clockid, &timo->cur);
683 timespecadd(&timo->cur, timeout, &timo->end);
684 } else {
685 timo->end = *timeout;
686 timo->is_abs_real = clockid == CLOCK_REALTIME ||
687 clockid == CLOCK_REALTIME_FAST ||
688 clockid == CLOCK_REALTIME_PRECISE ||
689 clockid == CLOCK_SECOND;
690 }
691 }
692
693 static void
umtx_abs_timeout_init2(struct umtx_abs_timeout * timo,const struct _umtx_time * umtxtime)694 umtx_abs_timeout_init2(struct umtx_abs_timeout *timo,
695 const struct _umtx_time *umtxtime)
696 {
697
698 umtx_abs_timeout_init(timo, umtxtime->_clockid,
699 (umtxtime->_flags & UMTX_ABSTIME) != 0, &umtxtime->_timeout);
700 }
701
702 static void
umtx_abs_timeout_enforce_min(sbintime_t * sbt)703 umtx_abs_timeout_enforce_min(sbintime_t *sbt)
704 {
705 sbintime_t when, mint;
706
707 mint = curproc->p_umtx_min_timeout;
708 if (__predict_false(mint != 0)) {
709 when = sbinuptime() + mint;
710 if (*sbt < when)
711 *sbt = when;
712 }
713 }
714
715 static int
umtx_abs_timeout_getsbt(struct umtx_abs_timeout * timo,sbintime_t * sbt,int * flags)716 umtx_abs_timeout_getsbt(struct umtx_abs_timeout *timo, sbintime_t *sbt,
717 int *flags)
718 {
719 struct bintime bt, bbt;
720 struct timespec tts;
721 sbintime_t rem;
722
723 switch (timo->clockid) {
724
725 /* Clocks that can be converted into absolute time. */
726 case CLOCK_REALTIME:
727 case CLOCK_REALTIME_PRECISE:
728 case CLOCK_REALTIME_FAST:
729 case CLOCK_MONOTONIC:
730 case CLOCK_MONOTONIC_PRECISE:
731 case CLOCK_MONOTONIC_FAST:
732 case CLOCK_UPTIME:
733 case CLOCK_UPTIME_PRECISE:
734 case CLOCK_UPTIME_FAST:
735 case CLOCK_SECOND:
736 timespec2bintime(&timo->end, &bt);
737 switch (timo->clockid) {
738 case CLOCK_REALTIME:
739 case CLOCK_REALTIME_PRECISE:
740 case CLOCK_REALTIME_FAST:
741 case CLOCK_SECOND:
742 getboottimebin(&bbt);
743 bintime_sub(&bt, &bbt);
744 break;
745 }
746 if (bt.sec < 0)
747 return (ETIMEDOUT);
748 if (bt.sec >= (SBT_MAX >> 32)) {
749 *sbt = 0;
750 *flags = 0;
751 return (0);
752 }
753 *sbt = bttosbt(bt);
754 umtx_abs_timeout_enforce_min(sbt);
755
756 /*
757 * Check if the absolute time should be aligned to
758 * avoid firing multiple timer events in non-periodic
759 * timer mode.
760 */
761 switch (timo->clockid) {
762 case CLOCK_REALTIME_FAST:
763 case CLOCK_MONOTONIC_FAST:
764 case CLOCK_UPTIME_FAST:
765 rem = *sbt % tc_tick_sbt;
766 if (__predict_true(rem != 0))
767 *sbt += tc_tick_sbt - rem;
768 break;
769 case CLOCK_SECOND:
770 rem = *sbt % SBT_1S;
771 if (__predict_true(rem != 0))
772 *sbt += SBT_1S - rem;
773 break;
774 }
775 *flags = C_ABSOLUTE;
776 return (0);
777
778 /* Clocks that has to be periodically polled. */
779 case CLOCK_VIRTUAL:
780 case CLOCK_PROF:
781 case CLOCK_THREAD_CPUTIME_ID:
782 case CLOCK_PROCESS_CPUTIME_ID:
783 default:
784 kern_clock_gettime(curthread, timo->clockid, &timo->cur);
785 if (timespeccmp(&timo->end, &timo->cur, <=))
786 return (ETIMEDOUT);
787 timespecsub(&timo->end, &timo->cur, &tts);
788 *sbt = tick_sbt * tstohz(&tts);
789 *flags = C_HARDCLOCK;
790 return (0);
791 }
792 }
793
794 static uint32_t
umtx_unlock_val(uint32_t flags,bool rb)795 umtx_unlock_val(uint32_t flags, bool rb)
796 {
797
798 if (rb)
799 return (UMUTEX_RB_OWNERDEAD);
800 else if ((flags & UMUTEX_NONCONSISTENT) != 0)
801 return (UMUTEX_RB_NOTRECOV);
802 else
803 return (UMUTEX_UNOWNED);
804
805 }
806
807 /*
808 * Put thread into sleep state, before sleeping, check if
809 * thread was removed from umtx queue.
810 */
811 int
umtxq_sleep(struct umtx_q * uq,const char * wmesg,struct umtx_abs_timeout * timo)812 umtxq_sleep(struct umtx_q *uq, const char *wmesg,
813 struct umtx_abs_timeout *timo)
814 {
815 struct umtxq_chain *uc;
816 sbintime_t sbt = 0;
817 int error, flags = 0;
818
819 uc = umtxq_getchain(&uq->uq_key);
820 UMTXQ_LOCKED_ASSERT(uc);
821 for (;;) {
822 if (!(uq->uq_flags & UQF_UMTXQ)) {
823 error = 0;
824 break;
825 }
826 if (timo != NULL) {
827 if (timo->is_abs_real)
828 curthread->td_rtcgen =
829 atomic_load_acq_int(&rtc_generation);
830 error = umtx_abs_timeout_getsbt(timo, &sbt, &flags);
831 if (error != 0)
832 break;
833 }
834 error = msleep_sbt(uq, &uc->uc_lock, PCATCH | PDROP, wmesg,
835 sbt, 0, flags);
836 uc = umtxq_getchain(&uq->uq_key);
837 mtx_lock(&uc->uc_lock);
838 if (error == EINTR || error == ERESTART)
839 break;
840 if (error == EWOULDBLOCK && (flags & C_ABSOLUTE) != 0) {
841 error = ETIMEDOUT;
842 break;
843 }
844 }
845
846 curthread->td_rtcgen = 0;
847 return (error);
848 }
849
850 /*
851 * Convert userspace address into unique logical address.
852 */
853 int
umtx_key_get(const void * addr,int type,int share,struct umtx_key * key)854 umtx_key_get(const void *addr, int type, int share, struct umtx_key *key)
855 {
856 struct thread *td = curthread;
857 vm_map_t map;
858 vm_map_entry_t entry;
859 vm_pindex_t pindex;
860 vm_prot_t prot;
861 boolean_t wired;
862
863 key->type = type;
864 if (share == THREAD_SHARE) {
865 key->shared = 0;
866 key->info.private.vs = td->td_proc->p_vmspace;
867 key->info.private.addr = (uintptr_t)addr;
868 } else {
869 MPASS(share == PROCESS_SHARE || share == AUTO_SHARE);
870 map = &td->td_proc->p_vmspace->vm_map;
871 if (vm_map_lookup(&map, (vm_offset_t)addr, VM_PROT_WRITE,
872 &entry, &key->info.shared.object, &pindex, &prot,
873 &wired) != KERN_SUCCESS) {
874 return (EFAULT);
875 }
876
877 if ((share == PROCESS_SHARE) ||
878 (share == AUTO_SHARE &&
879 VM_INHERIT_SHARE == entry->inheritance)) {
880 key->shared = 1;
881 key->info.shared.offset = (vm_offset_t)addr -
882 entry->start + entry->offset;
883 vm_object_reference(key->info.shared.object);
884 } else {
885 key->shared = 0;
886 key->info.private.vs = td->td_proc->p_vmspace;
887 key->info.private.addr = (uintptr_t)addr;
888 }
889 vm_map_lookup_done(map, entry);
890 }
891
892 umtxq_hash(key);
893 return (0);
894 }
895
896 /*
897 * Release key.
898 */
899 void
umtx_key_release(struct umtx_key * key)900 umtx_key_release(struct umtx_key *key)
901 {
902 if (key->shared)
903 vm_object_deallocate(key->info.shared.object);
904 }
905
906 #ifdef COMPAT_FREEBSD10
907 /*
908 * Lock a umtx object.
909 */
910 static int
do_lock_umtx(struct thread * td,struct umtx * umtx,u_long id,const struct timespec * timeout)911 do_lock_umtx(struct thread *td, struct umtx *umtx, u_long id,
912 const struct timespec *timeout)
913 {
914 struct umtx_abs_timeout timo;
915 struct umtx_q *uq;
916 u_long owner;
917 u_long old;
918 int error = 0;
919
920 uq = td->td_umtxq;
921 if (timeout != NULL)
922 umtx_abs_timeout_init(&timo, CLOCK_REALTIME, 0, timeout);
923
924 /*
925 * Care must be exercised when dealing with umtx structure. It
926 * can fault on any access.
927 */
928 for (;;) {
929 /*
930 * Try the uncontested case. This should be done in userland.
931 */
932 owner = casuword(&umtx->u_owner, UMTX_UNOWNED, id);
933
934 /* The acquire succeeded. */
935 if (owner == UMTX_UNOWNED)
936 return (0);
937
938 /* The address was invalid. */
939 if (owner == -1)
940 return (EFAULT);
941
942 /* If no one owns it but it is contested try to acquire it. */
943 if (owner == UMTX_CONTESTED) {
944 owner = casuword(&umtx->u_owner,
945 UMTX_CONTESTED, id | UMTX_CONTESTED);
946
947 if (owner == UMTX_CONTESTED)
948 return (0);
949
950 /* The address was invalid. */
951 if (owner == -1)
952 return (EFAULT);
953
954 error = thread_check_susp(td, false);
955 if (error != 0)
956 break;
957
958 /* If this failed the lock has changed, restart. */
959 continue;
960 }
961
962 /*
963 * If we caught a signal, we have retried and now
964 * exit immediately.
965 */
966 if (error != 0)
967 break;
968
969 if ((error = umtx_key_get(umtx, TYPE_SIMPLE_LOCK,
970 AUTO_SHARE, &uq->uq_key)) != 0)
971 return (error);
972
973 umtxq_lock(&uq->uq_key);
974 umtxq_busy(&uq->uq_key);
975 umtxq_insert(uq);
976 umtxq_unbusy(&uq->uq_key);
977 umtxq_unlock(&uq->uq_key);
978
979 /*
980 * Set the contested bit so that a release in user space
981 * knows to use the system call for unlock. If this fails
982 * either some one else has acquired the lock or it has been
983 * released.
984 */
985 old = casuword(&umtx->u_owner, owner, owner | UMTX_CONTESTED);
986
987 /* The address was invalid. */
988 if (old == -1) {
989 umtxq_lock(&uq->uq_key);
990 umtxq_remove(uq);
991 umtxq_unlock(&uq->uq_key);
992 umtx_key_release(&uq->uq_key);
993 return (EFAULT);
994 }
995
996 /*
997 * We set the contested bit, sleep. Otherwise the lock changed
998 * and we need to retry or we lost a race to the thread
999 * unlocking the umtx.
1000 */
1001 umtxq_lock(&uq->uq_key);
1002 if (old == owner)
1003 error = umtxq_sleep(uq, "umtx", timeout == NULL ? NULL :
1004 &timo);
1005 umtxq_remove(uq);
1006 umtxq_unlock(&uq->uq_key);
1007 umtx_key_release(&uq->uq_key);
1008
1009 if (error == 0)
1010 error = thread_check_susp(td, false);
1011 }
1012
1013 if (timeout == NULL) {
1014 /* Mutex locking is restarted if it is interrupted. */
1015 if (error == EINTR)
1016 error = ERESTART;
1017 } else {
1018 /* Timed-locking is not restarted. */
1019 if (error == ERESTART)
1020 error = EINTR;
1021 }
1022 return (error);
1023 }
1024
1025 /*
1026 * Unlock a umtx object.
1027 */
1028 static int
do_unlock_umtx(struct thread * td,struct umtx * umtx,u_long id)1029 do_unlock_umtx(struct thread *td, struct umtx *umtx, u_long id)
1030 {
1031 struct umtx_key key;
1032 u_long owner;
1033 u_long old;
1034 int error;
1035 int count;
1036
1037 /*
1038 * Make sure we own this mtx.
1039 */
1040 owner = fuword(__DEVOLATILE(u_long *, &umtx->u_owner));
1041 if (owner == -1)
1042 return (EFAULT);
1043
1044 if ((owner & ~UMTX_CONTESTED) != id)
1045 return (EPERM);
1046
1047 /* This should be done in userland */
1048 if ((owner & UMTX_CONTESTED) == 0) {
1049 old = casuword(&umtx->u_owner, owner, UMTX_UNOWNED);
1050 if (old == -1)
1051 return (EFAULT);
1052 if (old == owner)
1053 return (0);
1054 owner = old;
1055 }
1056
1057 /* We should only ever be in here for contested locks */
1058 if ((error = umtx_key_get(umtx, TYPE_SIMPLE_LOCK, AUTO_SHARE,
1059 &key)) != 0)
1060 return (error);
1061
1062 umtxq_lock(&key);
1063 umtxq_busy(&key);
1064 count = umtxq_count(&key);
1065 umtxq_unlock(&key);
1066
1067 /*
1068 * When unlocking the umtx, it must be marked as unowned if
1069 * there is zero or one thread only waiting for it.
1070 * Otherwise, it must be marked as contested.
1071 */
1072 old = casuword(&umtx->u_owner, owner,
1073 count <= 1 ? UMTX_UNOWNED : UMTX_CONTESTED);
1074 umtxq_lock(&key);
1075 umtxq_signal(&key,1);
1076 umtxq_unbusy(&key);
1077 umtxq_unlock(&key);
1078 umtx_key_release(&key);
1079 if (old == -1)
1080 return (EFAULT);
1081 if (old != owner)
1082 return (EINVAL);
1083 return (0);
1084 }
1085
1086 #ifdef COMPAT_FREEBSD32
1087
1088 /*
1089 * Lock a umtx object.
1090 */
1091 static int
do_lock_umtx32(struct thread * td,uint32_t * m,uint32_t id,const struct timespec * timeout)1092 do_lock_umtx32(struct thread *td, uint32_t *m, uint32_t id,
1093 const struct timespec *timeout)
1094 {
1095 struct umtx_abs_timeout timo;
1096 struct umtx_q *uq;
1097 uint32_t owner;
1098 uint32_t old;
1099 int error = 0;
1100
1101 uq = td->td_umtxq;
1102
1103 if (timeout != NULL)
1104 umtx_abs_timeout_init(&timo, CLOCK_REALTIME, 0, timeout);
1105
1106 /*
1107 * Care must be exercised when dealing with umtx structure. It
1108 * can fault on any access.
1109 */
1110 for (;;) {
1111 /*
1112 * Try the uncontested case. This should be done in userland.
1113 */
1114 owner = casuword32(m, UMUTEX_UNOWNED, id);
1115
1116 /* The acquire succeeded. */
1117 if (owner == UMUTEX_UNOWNED)
1118 return (0);
1119
1120 /* The address was invalid. */
1121 if (owner == -1)
1122 return (EFAULT);
1123
1124 /* If no one owns it but it is contested try to acquire it. */
1125 if (owner == UMUTEX_CONTESTED) {
1126 owner = casuword32(m,
1127 UMUTEX_CONTESTED, id | UMUTEX_CONTESTED);
1128 if (owner == UMUTEX_CONTESTED)
1129 return (0);
1130
1131 /* The address was invalid. */
1132 if (owner == -1)
1133 return (EFAULT);
1134
1135 error = thread_check_susp(td, false);
1136 if (error != 0)
1137 break;
1138
1139 /* If this failed the lock has changed, restart. */
1140 continue;
1141 }
1142
1143 /*
1144 * If we caught a signal, we have retried and now
1145 * exit immediately.
1146 */
1147 if (error != 0)
1148 return (error);
1149
1150 if ((error = umtx_key_get(m, TYPE_SIMPLE_LOCK,
1151 AUTO_SHARE, &uq->uq_key)) != 0)
1152 return (error);
1153
1154 umtxq_lock(&uq->uq_key);
1155 umtxq_busy(&uq->uq_key);
1156 umtxq_insert(uq);
1157 umtxq_unbusy(&uq->uq_key);
1158 umtxq_unlock(&uq->uq_key);
1159
1160 /*
1161 * Set the contested bit so that a release in user space
1162 * knows to use the system call for unlock. If this fails
1163 * either some one else has acquired the lock or it has been
1164 * released.
1165 */
1166 old = casuword32(m, owner, owner | UMUTEX_CONTESTED);
1167
1168 /* The address was invalid. */
1169 if (old == -1) {
1170 umtxq_lock(&uq->uq_key);
1171 umtxq_remove(uq);
1172 umtxq_unlock(&uq->uq_key);
1173 umtx_key_release(&uq->uq_key);
1174 return (EFAULT);
1175 }
1176
1177 /*
1178 * We set the contested bit, sleep. Otherwise the lock changed
1179 * and we need to retry or we lost a race to the thread
1180 * unlocking the umtx.
1181 */
1182 umtxq_lock(&uq->uq_key);
1183 if (old == owner)
1184 error = umtxq_sleep(uq, "umtx", timeout == NULL ?
1185 NULL : &timo);
1186 umtxq_remove(uq);
1187 umtxq_unlock(&uq->uq_key);
1188 umtx_key_release(&uq->uq_key);
1189
1190 if (error == 0)
1191 error = thread_check_susp(td, false);
1192 }
1193
1194 if (timeout == NULL) {
1195 /* Mutex locking is restarted if it is interrupted. */
1196 if (error == EINTR)
1197 error = ERESTART;
1198 } else {
1199 /* Timed-locking is not restarted. */
1200 if (error == ERESTART)
1201 error = EINTR;
1202 }
1203 return (error);
1204 }
1205
1206 /*
1207 * Unlock a umtx object.
1208 */
1209 static int
do_unlock_umtx32(struct thread * td,uint32_t * m,uint32_t id)1210 do_unlock_umtx32(struct thread *td, uint32_t *m, uint32_t id)
1211 {
1212 struct umtx_key key;
1213 uint32_t owner;
1214 uint32_t old;
1215 int error;
1216 int count;
1217
1218 /*
1219 * Make sure we own this mtx.
1220 */
1221 owner = fuword32(m);
1222 if (owner == -1)
1223 return (EFAULT);
1224
1225 if ((owner & ~UMUTEX_CONTESTED) != id)
1226 return (EPERM);
1227
1228 /* This should be done in userland */
1229 if ((owner & UMUTEX_CONTESTED) == 0) {
1230 old = casuword32(m, owner, UMUTEX_UNOWNED);
1231 if (old == -1)
1232 return (EFAULT);
1233 if (old == owner)
1234 return (0);
1235 owner = old;
1236 }
1237
1238 /* We should only ever be in here for contested locks */
1239 if ((error = umtx_key_get(m, TYPE_SIMPLE_LOCK, AUTO_SHARE,
1240 &key)) != 0)
1241 return (error);
1242
1243 umtxq_lock(&key);
1244 umtxq_busy(&key);
1245 count = umtxq_count(&key);
1246 umtxq_unlock(&key);
1247
1248 /*
1249 * When unlocking the umtx, it must be marked as unowned if
1250 * there is zero or one thread only waiting for it.
1251 * Otherwise, it must be marked as contested.
1252 */
1253 old = casuword32(m, owner,
1254 count <= 1 ? UMUTEX_UNOWNED : UMUTEX_CONTESTED);
1255 umtxq_lock(&key);
1256 umtxq_signal(&key,1);
1257 umtxq_unbusy(&key);
1258 umtxq_unlock(&key);
1259 umtx_key_release(&key);
1260 if (old == -1)
1261 return (EFAULT);
1262 if (old != owner)
1263 return (EINVAL);
1264 return (0);
1265 }
1266 #endif /* COMPAT_FREEBSD32 */
1267 #endif /* COMPAT_FREEBSD10 */
1268
1269 /*
1270 * Fetch and compare value, sleep on the address if value is not changed.
1271 */
1272 static int
do_wait(struct thread * td,void * addr,u_long id,struct _umtx_time * timeout,int compat32,int is_private)1273 do_wait(struct thread *td, void *addr, u_long id,
1274 struct _umtx_time *timeout, int compat32, int is_private)
1275 {
1276 struct umtx_abs_timeout timo;
1277 struct umtx_q *uq;
1278 u_long tmp;
1279 uint32_t tmp32;
1280 int error = 0;
1281
1282 uq = td->td_umtxq;
1283 if ((error = umtx_key_get(addr, TYPE_SIMPLE_WAIT,
1284 is_private ? THREAD_SHARE : AUTO_SHARE, &uq->uq_key)) != 0)
1285 return (error);
1286
1287 if (timeout != NULL)
1288 umtx_abs_timeout_init2(&timo, timeout);
1289
1290 umtxq_lock(&uq->uq_key);
1291 umtxq_insert(uq);
1292 umtxq_unlock(&uq->uq_key);
1293 if (compat32 == 0) {
1294 error = fueword(addr, &tmp);
1295 if (error != 0)
1296 error = EFAULT;
1297 } else {
1298 error = fueword32(addr, &tmp32);
1299 if (error == 0)
1300 tmp = tmp32;
1301 else
1302 error = EFAULT;
1303 }
1304 umtxq_lock(&uq->uq_key);
1305 if (error == 0) {
1306 if (tmp == id)
1307 error = umtxq_sleep(uq, "uwait", timeout == NULL ?
1308 NULL : &timo);
1309 if ((uq->uq_flags & UQF_UMTXQ) == 0)
1310 error = 0;
1311 else
1312 umtxq_remove(uq);
1313 } else if ((uq->uq_flags & UQF_UMTXQ) != 0) {
1314 umtxq_remove(uq);
1315 }
1316 umtxq_unlock(&uq->uq_key);
1317 umtx_key_release(&uq->uq_key);
1318 if (error == ERESTART)
1319 error = EINTR;
1320 return (error);
1321 }
1322
1323 /*
1324 * Wake up threads sleeping on the specified address.
1325 */
1326 int
kern_umtx_wake(struct thread * td,void * uaddr,int n_wake,int is_private)1327 kern_umtx_wake(struct thread *td, void *uaddr, int n_wake, int is_private)
1328 {
1329 struct umtx_key key;
1330 int ret;
1331
1332 if ((ret = umtx_key_get(uaddr, TYPE_SIMPLE_WAIT,
1333 is_private ? THREAD_SHARE : AUTO_SHARE, &key)) != 0)
1334 return (ret);
1335 umtxq_lock(&key);
1336 umtxq_signal(&key, n_wake);
1337 umtxq_unlock(&key);
1338 umtx_key_release(&key);
1339 return (0);
1340 }
1341
1342 /*
1343 * Lock PTHREAD_PRIO_NONE protocol POSIX mutex.
1344 */
1345 static int
do_lock_normal(struct thread * td,struct umutex * m,uint32_t flags,struct _umtx_time * timeout,int mode)1346 do_lock_normal(struct thread *td, struct umutex *m, uint32_t flags,
1347 struct _umtx_time *timeout, int mode)
1348 {
1349 struct umtx_abs_timeout timo;
1350 struct umtx_q *uq;
1351 uint32_t owner, old, id;
1352 int error, rv;
1353
1354 id = td->td_tid;
1355 uq = td->td_umtxq;
1356 error = 0;
1357 if (timeout != NULL)
1358 umtx_abs_timeout_init2(&timo, timeout);
1359
1360 /*
1361 * Care must be exercised when dealing with umtx structure. It
1362 * can fault on any access.
1363 */
1364 for (;;) {
1365 rv = fueword32(&m->m_owner, &owner);
1366 if (rv == -1)
1367 return (EFAULT);
1368 if (mode == _UMUTEX_WAIT) {
1369 if (owner == UMUTEX_UNOWNED ||
1370 owner == UMUTEX_CONTESTED ||
1371 owner == UMUTEX_RB_OWNERDEAD ||
1372 owner == UMUTEX_RB_NOTRECOV)
1373 return (0);
1374 } else {
1375 /*
1376 * Robust mutex terminated. Kernel duty is to
1377 * return EOWNERDEAD to the userspace. The
1378 * umutex.m_flags UMUTEX_NONCONSISTENT is set
1379 * by the common userspace code.
1380 */
1381 if (owner == UMUTEX_RB_OWNERDEAD) {
1382 rv = casueword32(&m->m_owner,
1383 UMUTEX_RB_OWNERDEAD, &owner,
1384 id | UMUTEX_CONTESTED);
1385 if (rv == -1)
1386 return (EFAULT);
1387 if (rv == 0) {
1388 MPASS(owner == UMUTEX_RB_OWNERDEAD);
1389 return (EOWNERDEAD); /* success */
1390 }
1391 MPASS(rv == 1);
1392 rv = thread_check_susp(td, false);
1393 if (rv != 0)
1394 return (rv);
1395 continue;
1396 }
1397 if (owner == UMUTEX_RB_NOTRECOV)
1398 return (ENOTRECOVERABLE);
1399
1400 /*
1401 * Try the uncontested case. This should be
1402 * done in userland.
1403 */
1404 rv = casueword32(&m->m_owner, UMUTEX_UNOWNED,
1405 &owner, id);
1406 /* The address was invalid. */
1407 if (rv == -1)
1408 return (EFAULT);
1409
1410 /* The acquire succeeded. */
1411 if (rv == 0) {
1412 MPASS(owner == UMUTEX_UNOWNED);
1413 return (0);
1414 }
1415
1416 /*
1417 * If no one owns it but it is contested try
1418 * to acquire it.
1419 */
1420 MPASS(rv == 1);
1421 if (owner == UMUTEX_CONTESTED) {
1422 rv = casueword32(&m->m_owner,
1423 UMUTEX_CONTESTED, &owner,
1424 id | UMUTEX_CONTESTED);
1425 /* The address was invalid. */
1426 if (rv == -1)
1427 return (EFAULT);
1428 if (rv == 0) {
1429 MPASS(owner == UMUTEX_CONTESTED);
1430 return (0);
1431 }
1432 if (rv == 1) {
1433 rv = thread_check_susp(td, false);
1434 if (rv != 0)
1435 return (rv);
1436 }
1437
1438 /*
1439 * If this failed the lock has
1440 * changed, restart.
1441 */
1442 continue;
1443 }
1444
1445 /* rv == 1 but not contested, likely store failure */
1446 rv = thread_check_susp(td, false);
1447 if (rv != 0)
1448 return (rv);
1449 }
1450
1451 if (mode == _UMUTEX_TRY)
1452 return (EBUSY);
1453
1454 /*
1455 * If we caught a signal, we have retried and now
1456 * exit immediately.
1457 */
1458 if (error != 0)
1459 return (error);
1460
1461 if ((error = umtx_key_get(m, TYPE_NORMAL_UMUTEX,
1462 GET_SHARE(flags), &uq->uq_key)) != 0)
1463 return (error);
1464
1465 umtxq_lock(&uq->uq_key);
1466 umtxq_busy(&uq->uq_key);
1467 umtxq_insert(uq);
1468 umtxq_unlock(&uq->uq_key);
1469
1470 /*
1471 * Set the contested bit so that a release in user space
1472 * knows to use the system call for unlock. If this fails
1473 * either some one else has acquired the lock or it has been
1474 * released.
1475 */
1476 rv = casueword32(&m->m_owner, owner, &old,
1477 owner | UMUTEX_CONTESTED);
1478
1479 /* The address was invalid or casueword failed to store. */
1480 if (rv == -1 || rv == 1) {
1481 umtxq_lock(&uq->uq_key);
1482 umtxq_remove(uq);
1483 umtxq_unbusy(&uq->uq_key);
1484 umtxq_unlock(&uq->uq_key);
1485 umtx_key_release(&uq->uq_key);
1486 if (rv == -1)
1487 return (EFAULT);
1488 if (rv == 1) {
1489 rv = thread_check_susp(td, false);
1490 if (rv != 0)
1491 return (rv);
1492 }
1493 continue;
1494 }
1495
1496 /*
1497 * We set the contested bit, sleep. Otherwise the lock changed
1498 * and we need to retry or we lost a race to the thread
1499 * unlocking the umtx.
1500 */
1501 umtxq_lock(&uq->uq_key);
1502 umtxq_unbusy(&uq->uq_key);
1503 MPASS(old == owner);
1504 error = umtxq_sleep(uq, "umtxn", timeout == NULL ?
1505 NULL : &timo);
1506 umtxq_remove(uq);
1507 umtxq_unlock(&uq->uq_key);
1508 umtx_key_release(&uq->uq_key);
1509
1510 if (error == 0)
1511 error = thread_check_susp(td, false);
1512 }
1513
1514 return (0);
1515 }
1516
1517 /*
1518 * Unlock PTHREAD_PRIO_NONE protocol POSIX mutex.
1519 */
1520 static int
do_unlock_normal(struct thread * td,struct umutex * m,uint32_t flags,bool rb)1521 do_unlock_normal(struct thread *td, struct umutex *m, uint32_t flags, bool rb)
1522 {
1523 struct umtx_key key;
1524 uint32_t owner, old, id, newlock;
1525 int error, count;
1526
1527 id = td->td_tid;
1528
1529 again:
1530 /*
1531 * Make sure we own this mtx.
1532 */
1533 error = fueword32(&m->m_owner, &owner);
1534 if (error == -1)
1535 return (EFAULT);
1536
1537 if ((owner & ~UMUTEX_CONTESTED) != id)
1538 return (EPERM);
1539
1540 newlock = umtx_unlock_val(flags, rb);
1541 if ((owner & UMUTEX_CONTESTED) == 0) {
1542 error = casueword32(&m->m_owner, owner, &old, newlock);
1543 if (error == -1)
1544 return (EFAULT);
1545 if (error == 1) {
1546 error = thread_check_susp(td, false);
1547 if (error != 0)
1548 return (error);
1549 goto again;
1550 }
1551 MPASS(old == owner);
1552 return (0);
1553 }
1554
1555 /* We should only ever be in here for contested locks */
1556 if ((error = umtx_key_get(m, TYPE_NORMAL_UMUTEX, GET_SHARE(flags),
1557 &key)) != 0)
1558 return (error);
1559
1560 umtxq_lock(&key);
1561 umtxq_busy(&key);
1562 count = umtxq_count(&key);
1563 umtxq_unlock(&key);
1564
1565 /*
1566 * When unlocking the umtx, it must be marked as unowned if
1567 * there is zero or one thread only waiting for it.
1568 * Otherwise, it must be marked as contested.
1569 */
1570 if (count > 1)
1571 newlock |= UMUTEX_CONTESTED;
1572 error = casueword32(&m->m_owner, owner, &old, newlock);
1573 umtxq_lock(&key);
1574 umtxq_signal(&key, 1);
1575 umtxq_unbusy(&key);
1576 umtxq_unlock(&key);
1577 umtx_key_release(&key);
1578 if (error == -1)
1579 return (EFAULT);
1580 if (error == 1) {
1581 if (old != owner)
1582 return (EINVAL);
1583 error = thread_check_susp(td, false);
1584 if (error != 0)
1585 return (error);
1586 goto again;
1587 }
1588 return (0);
1589 }
1590
1591 /*
1592 * Check if the mutex is available and wake up a waiter,
1593 * only for simple mutex.
1594 */
1595 static int
do_wake_umutex(struct thread * td,struct umutex * m)1596 do_wake_umutex(struct thread *td, struct umutex *m)
1597 {
1598 struct umtx_key key;
1599 uint32_t owner;
1600 uint32_t flags;
1601 int error;
1602 int count;
1603
1604 again:
1605 error = fueword32(&m->m_owner, &owner);
1606 if (error == -1)
1607 return (EFAULT);
1608
1609 if ((owner & ~UMUTEX_CONTESTED) != 0 && owner != UMUTEX_RB_OWNERDEAD &&
1610 owner != UMUTEX_RB_NOTRECOV)
1611 return (0);
1612
1613 error = fueword32(&m->m_flags, &flags);
1614 if (error == -1)
1615 return (EFAULT);
1616
1617 /* We should only ever be in here for contested locks */
1618 if ((error = umtx_key_get(m, TYPE_NORMAL_UMUTEX, GET_SHARE(flags),
1619 &key)) != 0)
1620 return (error);
1621
1622 umtxq_lock(&key);
1623 umtxq_busy(&key);
1624 count = umtxq_count(&key);
1625 umtxq_unlock(&key);
1626
1627 if (count <= 1 && owner != UMUTEX_RB_OWNERDEAD &&
1628 owner != UMUTEX_RB_NOTRECOV) {
1629 error = casueword32(&m->m_owner, UMUTEX_CONTESTED, &owner,
1630 UMUTEX_UNOWNED);
1631 if (error == -1) {
1632 error = EFAULT;
1633 } else if (error == 1) {
1634 umtxq_lock(&key);
1635 umtxq_unbusy(&key);
1636 umtxq_unlock(&key);
1637 umtx_key_release(&key);
1638 error = thread_check_susp(td, false);
1639 if (error != 0)
1640 return (error);
1641 goto again;
1642 }
1643 }
1644
1645 umtxq_lock(&key);
1646 if (error == 0 && count != 0) {
1647 MPASS((owner & ~UMUTEX_CONTESTED) == 0 ||
1648 owner == UMUTEX_RB_OWNERDEAD ||
1649 owner == UMUTEX_RB_NOTRECOV);
1650 umtxq_signal(&key, 1);
1651 }
1652 umtxq_unbusy(&key);
1653 umtxq_unlock(&key);
1654 umtx_key_release(&key);
1655 return (error);
1656 }
1657
1658 /*
1659 * Check if the mutex has waiters and tries to fix contention bit.
1660 */
1661 static int
do_wake2_umutex(struct thread * td,struct umutex * m,uint32_t flags)1662 do_wake2_umutex(struct thread *td, struct umutex *m, uint32_t flags)
1663 {
1664 struct umtx_key key;
1665 uint32_t owner, old;
1666 int type;
1667 int error;
1668 int count;
1669
1670 switch (flags & (UMUTEX_PRIO_INHERIT | UMUTEX_PRIO_PROTECT |
1671 UMUTEX_ROBUST)) {
1672 case 0:
1673 case UMUTEX_ROBUST:
1674 type = TYPE_NORMAL_UMUTEX;
1675 break;
1676 case UMUTEX_PRIO_INHERIT:
1677 type = TYPE_PI_UMUTEX;
1678 break;
1679 case (UMUTEX_PRIO_INHERIT | UMUTEX_ROBUST):
1680 type = TYPE_PI_ROBUST_UMUTEX;
1681 break;
1682 case UMUTEX_PRIO_PROTECT:
1683 type = TYPE_PP_UMUTEX;
1684 break;
1685 case (UMUTEX_PRIO_PROTECT | UMUTEX_ROBUST):
1686 type = TYPE_PP_ROBUST_UMUTEX;
1687 break;
1688 default:
1689 return (EINVAL);
1690 }
1691 if ((error = umtx_key_get(m, type, GET_SHARE(flags), &key)) != 0)
1692 return (error);
1693
1694 owner = 0;
1695 umtxq_lock(&key);
1696 umtxq_busy(&key);
1697 count = umtxq_count(&key);
1698 umtxq_unlock(&key);
1699
1700 error = fueword32(&m->m_owner, &owner);
1701 if (error == -1)
1702 error = EFAULT;
1703
1704 /*
1705 * Only repair contention bit if there is a waiter, this means
1706 * the mutex is still being referenced by userland code,
1707 * otherwise don't update any memory.
1708 */
1709 while (error == 0 && (owner & UMUTEX_CONTESTED) == 0 &&
1710 (count > 1 || (count == 1 && (owner & ~UMUTEX_CONTESTED) != 0))) {
1711 error = casueword32(&m->m_owner, owner, &old,
1712 owner | UMUTEX_CONTESTED);
1713 if (error == -1) {
1714 error = EFAULT;
1715 break;
1716 }
1717 if (error == 0) {
1718 MPASS(old == owner);
1719 break;
1720 }
1721 owner = old;
1722 error = thread_check_susp(td, false);
1723 }
1724
1725 umtxq_lock(&key);
1726 if (error == EFAULT) {
1727 umtxq_signal(&key, INT_MAX);
1728 } else if (count != 0 && ((owner & ~UMUTEX_CONTESTED) == 0 ||
1729 owner == UMUTEX_RB_OWNERDEAD || owner == UMUTEX_RB_NOTRECOV))
1730 umtxq_signal(&key, 1);
1731 umtxq_unbusy(&key);
1732 umtxq_unlock(&key);
1733 umtx_key_release(&key);
1734 return (error);
1735 }
1736
1737 struct umtx_pi *
umtx_pi_alloc(int flags)1738 umtx_pi_alloc(int flags)
1739 {
1740 struct umtx_pi *pi;
1741
1742 pi = uma_zalloc(umtx_pi_zone, M_ZERO | flags);
1743 TAILQ_INIT(&pi->pi_blocked);
1744 atomic_add_int(&umtx_pi_allocated, 1);
1745 return (pi);
1746 }
1747
1748 void
umtx_pi_free(struct umtx_pi * pi)1749 umtx_pi_free(struct umtx_pi *pi)
1750 {
1751 uma_zfree(umtx_pi_zone, pi);
1752 atomic_add_int(&umtx_pi_allocated, -1);
1753 }
1754
1755 /*
1756 * Adjust the thread's position on a pi_state after its priority has been
1757 * changed.
1758 */
1759 static int
umtx_pi_adjust_thread(struct umtx_pi * pi,struct thread * td)1760 umtx_pi_adjust_thread(struct umtx_pi *pi, struct thread *td)
1761 {
1762 struct umtx_q *uq, *uq1, *uq2;
1763 struct thread *td1;
1764
1765 mtx_assert(&umtx_lock, MA_OWNED);
1766 if (pi == NULL)
1767 return (0);
1768
1769 uq = td->td_umtxq;
1770
1771 /*
1772 * Check if the thread needs to be moved on the blocked chain.
1773 * It needs to be moved if either its priority is lower than
1774 * the previous thread or higher than the next thread.
1775 */
1776 uq1 = TAILQ_PREV(uq, umtxq_head, uq_lockq);
1777 uq2 = TAILQ_NEXT(uq, uq_lockq);
1778 if ((uq1 != NULL && UPRI(td) < UPRI(uq1->uq_thread)) ||
1779 (uq2 != NULL && UPRI(td) > UPRI(uq2->uq_thread))) {
1780 /*
1781 * Remove thread from blocked chain and determine where
1782 * it should be moved to.
1783 */
1784 TAILQ_REMOVE(&pi->pi_blocked, uq, uq_lockq);
1785 TAILQ_FOREACH(uq1, &pi->pi_blocked, uq_lockq) {
1786 td1 = uq1->uq_thread;
1787 MPASS(td1->td_proc->p_magic == P_MAGIC);
1788 if (UPRI(td1) > UPRI(td))
1789 break;
1790 }
1791
1792 if (uq1 == NULL)
1793 TAILQ_INSERT_TAIL(&pi->pi_blocked, uq, uq_lockq);
1794 else
1795 TAILQ_INSERT_BEFORE(uq1, uq, uq_lockq);
1796 }
1797 return (1);
1798 }
1799
1800 static struct umtx_pi *
umtx_pi_next(struct umtx_pi * pi)1801 umtx_pi_next(struct umtx_pi *pi)
1802 {
1803 struct umtx_q *uq_owner;
1804
1805 if (pi->pi_owner == NULL)
1806 return (NULL);
1807 uq_owner = pi->pi_owner->td_umtxq;
1808 if (uq_owner == NULL)
1809 return (NULL);
1810 return (uq_owner->uq_pi_blocked);
1811 }
1812
1813 /*
1814 * Floyd's Cycle-Finding Algorithm.
1815 */
1816 static bool
umtx_pi_check_loop(struct umtx_pi * pi)1817 umtx_pi_check_loop(struct umtx_pi *pi)
1818 {
1819 struct umtx_pi *pi1; /* fast iterator */
1820
1821 mtx_assert(&umtx_lock, MA_OWNED);
1822 if (pi == NULL)
1823 return (false);
1824 pi1 = pi;
1825 for (;;) {
1826 pi = umtx_pi_next(pi);
1827 if (pi == NULL)
1828 break;
1829 pi1 = umtx_pi_next(pi1);
1830 if (pi1 == NULL)
1831 break;
1832 pi1 = umtx_pi_next(pi1);
1833 if (pi1 == NULL)
1834 break;
1835 if (pi == pi1)
1836 return (true);
1837 }
1838 return (false);
1839 }
1840
1841 /*
1842 * Propagate priority when a thread is blocked on POSIX
1843 * PI mutex.
1844 */
1845 static void
umtx_propagate_priority(struct thread * td)1846 umtx_propagate_priority(struct thread *td)
1847 {
1848 struct umtx_q *uq;
1849 struct umtx_pi *pi;
1850 int pri;
1851
1852 mtx_assert(&umtx_lock, MA_OWNED);
1853 pri = UPRI(td);
1854 uq = td->td_umtxq;
1855 pi = uq->uq_pi_blocked;
1856 if (pi == NULL)
1857 return;
1858 if (umtx_pi_check_loop(pi))
1859 return;
1860
1861 for (;;) {
1862 td = pi->pi_owner;
1863 if (td == NULL || td == curthread)
1864 return;
1865
1866 MPASS(td->td_proc != NULL);
1867 MPASS(td->td_proc->p_magic == P_MAGIC);
1868
1869 thread_lock(td);
1870 if (td->td_lend_user_pri > pri)
1871 sched_lend_user_prio(td, pri);
1872 else {
1873 thread_unlock(td);
1874 break;
1875 }
1876 thread_unlock(td);
1877
1878 /*
1879 * Pick up the lock that td is blocked on.
1880 */
1881 uq = td->td_umtxq;
1882 pi = uq->uq_pi_blocked;
1883 if (pi == NULL)
1884 break;
1885 /* Resort td on the list if needed. */
1886 umtx_pi_adjust_thread(pi, td);
1887 }
1888 }
1889
1890 /*
1891 * Unpropagate priority for a PI mutex when a thread blocked on
1892 * it is interrupted by signal or resumed by others.
1893 */
1894 static void
umtx_repropagate_priority(struct umtx_pi * pi)1895 umtx_repropagate_priority(struct umtx_pi *pi)
1896 {
1897 struct umtx_q *uq, *uq_owner;
1898 struct umtx_pi *pi2;
1899 int pri;
1900
1901 mtx_assert(&umtx_lock, MA_OWNED);
1902
1903 if (umtx_pi_check_loop(pi))
1904 return;
1905 while (pi != NULL && pi->pi_owner != NULL) {
1906 pri = PRI_MAX;
1907 uq_owner = pi->pi_owner->td_umtxq;
1908
1909 TAILQ_FOREACH(pi2, &uq_owner->uq_pi_contested, pi_link) {
1910 uq = TAILQ_FIRST(&pi2->pi_blocked);
1911 if (uq != NULL) {
1912 if (pri > UPRI(uq->uq_thread))
1913 pri = UPRI(uq->uq_thread);
1914 }
1915 }
1916
1917 if (pri > uq_owner->uq_inherited_pri)
1918 pri = uq_owner->uq_inherited_pri;
1919 thread_lock(pi->pi_owner);
1920 sched_lend_user_prio(pi->pi_owner, pri);
1921 thread_unlock(pi->pi_owner);
1922 if ((pi = uq_owner->uq_pi_blocked) != NULL)
1923 umtx_pi_adjust_thread(pi, uq_owner->uq_thread);
1924 }
1925 }
1926
1927 /*
1928 * Insert a PI mutex into owned list.
1929 */
1930 static void
umtx_pi_setowner(struct umtx_pi * pi,struct thread * owner)1931 umtx_pi_setowner(struct umtx_pi *pi, struct thread *owner)
1932 {
1933 struct umtx_q *uq_owner;
1934
1935 uq_owner = owner->td_umtxq;
1936 mtx_assert(&umtx_lock, MA_OWNED);
1937 MPASS(pi->pi_owner == NULL);
1938 pi->pi_owner = owner;
1939 TAILQ_INSERT_TAIL(&uq_owner->uq_pi_contested, pi, pi_link);
1940 }
1941
1942 /*
1943 * Disown a PI mutex, and remove it from the owned list.
1944 */
1945 static void
umtx_pi_disown(struct umtx_pi * pi)1946 umtx_pi_disown(struct umtx_pi *pi)
1947 {
1948
1949 mtx_assert(&umtx_lock, MA_OWNED);
1950 TAILQ_REMOVE(&pi->pi_owner->td_umtxq->uq_pi_contested, pi, pi_link);
1951 pi->pi_owner = NULL;
1952 }
1953
1954 /*
1955 * Claim ownership of a PI mutex.
1956 */
1957 int
umtx_pi_claim(struct umtx_pi * pi,struct thread * owner)1958 umtx_pi_claim(struct umtx_pi *pi, struct thread *owner)
1959 {
1960 struct umtx_q *uq;
1961 int pri;
1962
1963 mtx_lock(&umtx_lock);
1964 if (pi->pi_owner == owner) {
1965 mtx_unlock(&umtx_lock);
1966 return (0);
1967 }
1968
1969 if (pi->pi_owner != NULL) {
1970 /*
1971 * userland may have already messed the mutex, sigh.
1972 */
1973 mtx_unlock(&umtx_lock);
1974 return (EPERM);
1975 }
1976 umtx_pi_setowner(pi, owner);
1977 uq = TAILQ_FIRST(&pi->pi_blocked);
1978 if (uq != NULL) {
1979 pri = UPRI(uq->uq_thread);
1980 thread_lock(owner);
1981 if (pri < UPRI(owner))
1982 sched_lend_user_prio(owner, pri);
1983 thread_unlock(owner);
1984 }
1985 mtx_unlock(&umtx_lock);
1986 return (0);
1987 }
1988
1989 /*
1990 * Adjust a thread's order position in its blocked PI mutex,
1991 * this may result new priority propagating process.
1992 */
1993 void
umtx_pi_adjust(struct thread * td,u_char oldpri)1994 umtx_pi_adjust(struct thread *td, u_char oldpri)
1995 {
1996 struct umtx_q *uq;
1997 struct umtx_pi *pi;
1998
1999 uq = td->td_umtxq;
2000 mtx_lock(&umtx_lock);
2001 /*
2002 * Pick up the lock that td is blocked on.
2003 */
2004 pi = uq->uq_pi_blocked;
2005 if (pi != NULL) {
2006 umtx_pi_adjust_thread(pi, td);
2007 umtx_repropagate_priority(pi);
2008 }
2009 mtx_unlock(&umtx_lock);
2010 }
2011
2012 /*
2013 * Sleep on a PI mutex.
2014 */
2015 int
umtxq_sleep_pi(struct umtx_q * uq,struct umtx_pi * pi,uint32_t owner,const char * wmesg,struct umtx_abs_timeout * timo,bool shared)2016 umtxq_sleep_pi(struct umtx_q *uq, struct umtx_pi *pi, uint32_t owner,
2017 const char *wmesg, struct umtx_abs_timeout *timo, bool shared)
2018 {
2019 struct thread *td, *td1;
2020 struct umtx_q *uq1;
2021 int error, pri;
2022 #ifdef INVARIANTS
2023 struct umtxq_chain *uc;
2024
2025 uc = umtxq_getchain(&pi->pi_key);
2026 #endif
2027 error = 0;
2028 td = uq->uq_thread;
2029 KASSERT(td == curthread, ("inconsistent uq_thread"));
2030 UMTXQ_LOCKED_ASSERT(umtxq_getchain(&uq->uq_key));
2031 KASSERT(uc->uc_busy != 0, ("umtx chain is not busy"));
2032 umtxq_insert(uq);
2033 mtx_lock(&umtx_lock);
2034 if (pi->pi_owner == NULL) {
2035 mtx_unlock(&umtx_lock);
2036 td1 = tdfind(owner, shared ? -1 : td->td_proc->p_pid);
2037 mtx_lock(&umtx_lock);
2038 if (td1 != NULL) {
2039 if (pi->pi_owner == NULL)
2040 umtx_pi_setowner(pi, td1);
2041 PROC_UNLOCK(td1->td_proc);
2042 }
2043 }
2044
2045 TAILQ_FOREACH(uq1, &pi->pi_blocked, uq_lockq) {
2046 pri = UPRI(uq1->uq_thread);
2047 if (pri > UPRI(td))
2048 break;
2049 }
2050
2051 if (uq1 != NULL)
2052 TAILQ_INSERT_BEFORE(uq1, uq, uq_lockq);
2053 else
2054 TAILQ_INSERT_TAIL(&pi->pi_blocked, uq, uq_lockq);
2055
2056 uq->uq_pi_blocked = pi;
2057 thread_lock(td);
2058 td->td_flags |= TDF_UPIBLOCKED;
2059 thread_unlock(td);
2060 umtx_propagate_priority(td);
2061 mtx_unlock(&umtx_lock);
2062 umtxq_unbusy(&uq->uq_key);
2063
2064 error = umtxq_sleep(uq, wmesg, timo);
2065 umtxq_remove(uq);
2066
2067 mtx_lock(&umtx_lock);
2068 uq->uq_pi_blocked = NULL;
2069 thread_lock(td);
2070 td->td_flags &= ~TDF_UPIBLOCKED;
2071 thread_unlock(td);
2072 TAILQ_REMOVE(&pi->pi_blocked, uq, uq_lockq);
2073 umtx_repropagate_priority(pi);
2074 mtx_unlock(&umtx_lock);
2075 umtxq_unlock(&uq->uq_key);
2076
2077 return (error);
2078 }
2079
2080 /*
2081 * Add reference count for a PI mutex.
2082 */
2083 void
umtx_pi_ref(struct umtx_pi * pi)2084 umtx_pi_ref(struct umtx_pi *pi)
2085 {
2086
2087 UMTXQ_LOCKED_ASSERT(umtxq_getchain(&pi->pi_key));
2088 pi->pi_refcount++;
2089 }
2090
2091 /*
2092 * Decrease reference count for a PI mutex, if the counter
2093 * is decreased to zero, its memory space is freed.
2094 */
2095 void
umtx_pi_unref(struct umtx_pi * pi)2096 umtx_pi_unref(struct umtx_pi *pi)
2097 {
2098 struct umtxq_chain *uc;
2099
2100 uc = umtxq_getchain(&pi->pi_key);
2101 UMTXQ_LOCKED_ASSERT(uc);
2102 KASSERT(pi->pi_refcount > 0, ("invalid reference count"));
2103 if (--pi->pi_refcount == 0) {
2104 mtx_lock(&umtx_lock);
2105 if (pi->pi_owner != NULL)
2106 umtx_pi_disown(pi);
2107 KASSERT(TAILQ_EMPTY(&pi->pi_blocked),
2108 ("blocked queue not empty"));
2109 mtx_unlock(&umtx_lock);
2110 TAILQ_REMOVE(&uc->uc_pi_list, pi, pi_hashlink);
2111 umtx_pi_free(pi);
2112 }
2113 }
2114
2115 /*
2116 * Find a PI mutex in hash table.
2117 */
2118 struct umtx_pi *
umtx_pi_lookup(struct umtx_key * key)2119 umtx_pi_lookup(struct umtx_key *key)
2120 {
2121 struct umtxq_chain *uc;
2122 struct umtx_pi *pi;
2123
2124 uc = umtxq_getchain(key);
2125 UMTXQ_LOCKED_ASSERT(uc);
2126
2127 TAILQ_FOREACH(pi, &uc->uc_pi_list, pi_hashlink) {
2128 if (umtx_key_match(&pi->pi_key, key)) {
2129 return (pi);
2130 }
2131 }
2132 return (NULL);
2133 }
2134
2135 /*
2136 * Insert a PI mutex into hash table.
2137 */
2138 void
umtx_pi_insert(struct umtx_pi * pi)2139 umtx_pi_insert(struct umtx_pi *pi)
2140 {
2141 struct umtxq_chain *uc;
2142
2143 uc = umtxq_getchain(&pi->pi_key);
2144 UMTXQ_LOCKED_ASSERT(uc);
2145 TAILQ_INSERT_TAIL(&uc->uc_pi_list, pi, pi_hashlink);
2146 }
2147
2148 /*
2149 * Drop a PI mutex and wakeup a top waiter.
2150 */
2151 int
umtx_pi_drop(struct thread * td,struct umtx_key * key,bool rb,int * count)2152 umtx_pi_drop(struct thread *td, struct umtx_key *key, bool rb, int *count)
2153 {
2154 struct umtx_q *uq_first, *uq_first2, *uq_me;
2155 struct umtx_pi *pi, *pi2;
2156 int pri;
2157
2158 UMTXQ_ASSERT_LOCKED_BUSY(key);
2159 *count = umtxq_count_pi(key, &uq_first);
2160 if (uq_first != NULL) {
2161 mtx_lock(&umtx_lock);
2162 pi = uq_first->uq_pi_blocked;
2163 KASSERT(pi != NULL, ("pi == NULL?"));
2164 if (pi->pi_owner != td && !(rb && pi->pi_owner == NULL)) {
2165 mtx_unlock(&umtx_lock);
2166 /* userland messed the mutex */
2167 return (EPERM);
2168 }
2169 uq_me = td->td_umtxq;
2170 if (pi->pi_owner == td)
2171 umtx_pi_disown(pi);
2172 /* get highest priority thread which is still sleeping. */
2173 uq_first = TAILQ_FIRST(&pi->pi_blocked);
2174 while (uq_first != NULL &&
2175 (uq_first->uq_flags & UQF_UMTXQ) == 0) {
2176 uq_first = TAILQ_NEXT(uq_first, uq_lockq);
2177 }
2178 pri = PRI_MAX;
2179 TAILQ_FOREACH(pi2, &uq_me->uq_pi_contested, pi_link) {
2180 uq_first2 = TAILQ_FIRST(&pi2->pi_blocked);
2181 if (uq_first2 != NULL) {
2182 if (pri > UPRI(uq_first2->uq_thread))
2183 pri = UPRI(uq_first2->uq_thread);
2184 }
2185 }
2186 thread_lock(td);
2187 sched_lend_user_prio(td, pri);
2188 thread_unlock(td);
2189 mtx_unlock(&umtx_lock);
2190 if (uq_first)
2191 umtxq_signal_thread(uq_first);
2192 } else {
2193 pi = umtx_pi_lookup(key);
2194 /*
2195 * A umtx_pi can exist if a signal or timeout removed the
2196 * last waiter from the umtxq, but there is still
2197 * a thread in do_lock_pi() holding the umtx_pi.
2198 */
2199 if (pi != NULL) {
2200 /*
2201 * The umtx_pi can be unowned, such as when a thread
2202 * has just entered do_lock_pi(), allocated the
2203 * umtx_pi, and unlocked the umtxq.
2204 * If the current thread owns it, it must disown it.
2205 */
2206 mtx_lock(&umtx_lock);
2207 if (pi->pi_owner == td)
2208 umtx_pi_disown(pi);
2209 mtx_unlock(&umtx_lock);
2210 }
2211 }
2212 return (0);
2213 }
2214
2215 /*
2216 * Lock a PI mutex.
2217 */
2218 static int
do_lock_pi(struct thread * td,struct umutex * m,uint32_t flags,struct _umtx_time * timeout,int try)2219 do_lock_pi(struct thread *td, struct umutex *m, uint32_t flags,
2220 struct _umtx_time *timeout, int try)
2221 {
2222 struct umtx_abs_timeout timo;
2223 struct umtx_q *uq;
2224 struct umtx_pi *pi, *new_pi;
2225 uint32_t id, old_owner, owner, old;
2226 int error, rv;
2227
2228 id = td->td_tid;
2229 uq = td->td_umtxq;
2230
2231 if ((error = umtx_key_get(m, (flags & UMUTEX_ROBUST) != 0 ?
2232 TYPE_PI_ROBUST_UMUTEX : TYPE_PI_UMUTEX, GET_SHARE(flags),
2233 &uq->uq_key)) != 0)
2234 return (error);
2235
2236 if (timeout != NULL)
2237 umtx_abs_timeout_init2(&timo, timeout);
2238
2239 umtxq_lock(&uq->uq_key);
2240 pi = umtx_pi_lookup(&uq->uq_key);
2241 if (pi == NULL) {
2242 new_pi = umtx_pi_alloc(M_NOWAIT);
2243 if (new_pi == NULL) {
2244 umtxq_unlock(&uq->uq_key);
2245 new_pi = umtx_pi_alloc(M_WAITOK);
2246 umtxq_lock(&uq->uq_key);
2247 pi = umtx_pi_lookup(&uq->uq_key);
2248 if (pi != NULL) {
2249 umtx_pi_free(new_pi);
2250 new_pi = NULL;
2251 }
2252 }
2253 if (new_pi != NULL) {
2254 new_pi->pi_key = uq->uq_key;
2255 umtx_pi_insert(new_pi);
2256 pi = new_pi;
2257 }
2258 }
2259 umtx_pi_ref(pi);
2260 umtxq_unlock(&uq->uq_key);
2261
2262 /*
2263 * Care must be exercised when dealing with umtx structure. It
2264 * can fault on any access.
2265 */
2266 for (;;) {
2267 /*
2268 * Try the uncontested case. This should be done in userland.
2269 */
2270 rv = casueword32(&m->m_owner, UMUTEX_UNOWNED, &owner, id);
2271 /* The address was invalid. */
2272 if (rv == -1) {
2273 error = EFAULT;
2274 break;
2275 }
2276 /* The acquire succeeded. */
2277 if (rv == 0) {
2278 MPASS(owner == UMUTEX_UNOWNED);
2279 error = 0;
2280 break;
2281 }
2282
2283 if (owner == UMUTEX_RB_NOTRECOV) {
2284 error = ENOTRECOVERABLE;
2285 break;
2286 }
2287
2288 /*
2289 * Nobody owns it, but the acquire failed. This can happen
2290 * with ll/sc atomics.
2291 */
2292 if (owner == UMUTEX_UNOWNED) {
2293 error = thread_check_susp(td, true);
2294 if (error != 0)
2295 break;
2296 continue;
2297 }
2298
2299 /*
2300 * Avoid overwriting a possible error from sleep due
2301 * to the pending signal with suspension check result.
2302 */
2303 if (error == 0) {
2304 error = thread_check_susp(td, true);
2305 if (error != 0)
2306 break;
2307 }
2308
2309 /* If no one owns it but it is contested try to acquire it. */
2310 if (owner == UMUTEX_CONTESTED || owner == UMUTEX_RB_OWNERDEAD) {
2311 old_owner = owner;
2312 rv = casueword32(&m->m_owner, owner, &owner,
2313 id | UMUTEX_CONTESTED);
2314 /* The address was invalid. */
2315 if (rv == -1) {
2316 error = EFAULT;
2317 break;
2318 }
2319 if (rv == 1) {
2320 if (error == 0) {
2321 error = thread_check_susp(td, true);
2322 if (error != 0)
2323 break;
2324 }
2325
2326 /*
2327 * If this failed the lock could
2328 * changed, restart.
2329 */
2330 continue;
2331 }
2332
2333 MPASS(rv == 0);
2334 MPASS(owner == old_owner);
2335 umtxq_lock(&uq->uq_key);
2336 umtxq_busy(&uq->uq_key);
2337 error = umtx_pi_claim(pi, td);
2338 umtxq_unbusy(&uq->uq_key);
2339 umtxq_unlock(&uq->uq_key);
2340 if (error != 0) {
2341 /*
2342 * Since we're going to return an
2343 * error, restore the m_owner to its
2344 * previous, unowned state to avoid
2345 * compounding the problem.
2346 */
2347 (void)casuword32(&m->m_owner,
2348 id | UMUTEX_CONTESTED, old_owner);
2349 }
2350 if (error == 0 && old_owner == UMUTEX_RB_OWNERDEAD)
2351 error = EOWNERDEAD;
2352 break;
2353 }
2354
2355 if ((owner & ~UMUTEX_CONTESTED) == id) {
2356 error = EDEADLK;
2357 break;
2358 }
2359
2360 if (try != 0) {
2361 error = EBUSY;
2362 break;
2363 }
2364
2365 /*
2366 * If we caught a signal, we have retried and now
2367 * exit immediately.
2368 */
2369 if (error != 0)
2370 break;
2371
2372 umtxq_lock(&uq->uq_key);
2373 umtxq_busy(&uq->uq_key);
2374 umtxq_unlock(&uq->uq_key);
2375
2376 /*
2377 * Set the contested bit so that a release in user space
2378 * knows to use the system call for unlock. If this fails
2379 * either some one else has acquired the lock or it has been
2380 * released.
2381 */
2382 rv = casueword32(&m->m_owner, owner, &old, owner |
2383 UMUTEX_CONTESTED);
2384
2385 /* The address was invalid. */
2386 if (rv == -1) {
2387 umtxq_unbusy_unlocked(&uq->uq_key);
2388 error = EFAULT;
2389 break;
2390 }
2391 if (rv == 1) {
2392 umtxq_unbusy_unlocked(&uq->uq_key);
2393 error = thread_check_susp(td, true);
2394 if (error != 0)
2395 break;
2396
2397 /*
2398 * The lock changed and we need to retry or we
2399 * lost a race to the thread unlocking the
2400 * umtx. Note that the UMUTEX_RB_OWNERDEAD
2401 * value for owner is impossible there.
2402 */
2403 continue;
2404 }
2405
2406 umtxq_lock(&uq->uq_key);
2407
2408 /* We set the contested bit, sleep. */
2409 MPASS(old == owner);
2410 error = umtxq_sleep_pi(uq, pi, owner & ~UMUTEX_CONTESTED,
2411 "umtxpi", timeout == NULL ? NULL : &timo,
2412 (flags & USYNC_PROCESS_SHARED) != 0);
2413 if (error != 0)
2414 continue;
2415
2416 error = thread_check_susp(td, false);
2417 if (error != 0)
2418 break;
2419 }
2420
2421 umtxq_lock(&uq->uq_key);
2422 umtx_pi_unref(pi);
2423 umtxq_unlock(&uq->uq_key);
2424
2425 umtx_key_release(&uq->uq_key);
2426 return (error);
2427 }
2428
2429 /*
2430 * Unlock a PI mutex.
2431 */
2432 static int
do_unlock_pi(struct thread * td,struct umutex * m,uint32_t flags,bool rb)2433 do_unlock_pi(struct thread *td, struct umutex *m, uint32_t flags, bool rb)
2434 {
2435 struct umtx_key key;
2436 uint32_t id, new_owner, old, owner;
2437 int count, error;
2438
2439 id = td->td_tid;
2440
2441 usrloop:
2442 /*
2443 * Make sure we own this mtx.
2444 */
2445 error = fueword32(&m->m_owner, &owner);
2446 if (error == -1)
2447 return (EFAULT);
2448
2449 if ((owner & ~UMUTEX_CONTESTED) != id)
2450 return (EPERM);
2451
2452 new_owner = umtx_unlock_val(flags, rb);
2453
2454 /* This should be done in userland */
2455 if ((owner & UMUTEX_CONTESTED) == 0) {
2456 error = casueword32(&m->m_owner, owner, &old, new_owner);
2457 if (error == -1)
2458 return (EFAULT);
2459 if (error == 1) {
2460 error = thread_check_susp(td, true);
2461 if (error != 0)
2462 return (error);
2463 goto usrloop;
2464 }
2465 if (old == owner)
2466 return (0);
2467 owner = old;
2468 }
2469
2470 /* We should only ever be in here for contested locks */
2471 if ((error = umtx_key_get(m, (flags & UMUTEX_ROBUST) != 0 ?
2472 TYPE_PI_ROBUST_UMUTEX : TYPE_PI_UMUTEX, GET_SHARE(flags),
2473 &key)) != 0)
2474 return (error);
2475
2476 umtxq_lock(&key);
2477 umtxq_busy(&key);
2478 error = umtx_pi_drop(td, &key, rb, &count);
2479 if (error != 0) {
2480 umtxq_unbusy(&key);
2481 umtxq_unlock(&key);
2482 umtx_key_release(&key);
2483 /* userland messed the mutex */
2484 return (error);
2485 }
2486 umtxq_unlock(&key);
2487
2488 /*
2489 * When unlocking the umtx, it must be marked as unowned if
2490 * there is zero or one thread only waiting for it.
2491 * Otherwise, it must be marked as contested.
2492 */
2493
2494 if (count > 1)
2495 new_owner |= UMUTEX_CONTESTED;
2496 again:
2497 error = casueword32(&m->m_owner, owner, &old, new_owner);
2498 if (error == 1) {
2499 error = thread_check_susp(td, false);
2500 if (error == 0)
2501 goto again;
2502 }
2503 umtxq_unbusy_unlocked(&key);
2504 umtx_key_release(&key);
2505 if (error == -1)
2506 return (EFAULT);
2507 if (error == 0 && old != owner)
2508 return (EINVAL);
2509 return (error);
2510 }
2511
2512 /*
2513 * Lock a PP mutex.
2514 */
2515 static int
do_lock_pp(struct thread * td,struct umutex * m,uint32_t flags,struct _umtx_time * timeout,int try)2516 do_lock_pp(struct thread *td, struct umutex *m, uint32_t flags,
2517 struct _umtx_time *timeout, int try)
2518 {
2519 struct umtx_abs_timeout timo;
2520 struct umtx_q *uq, *uq2;
2521 struct umtx_pi *pi;
2522 uint32_t ceiling;
2523 uint32_t owner, id;
2524 int error, pri, old_inherited_pri, new_pri, rv;
2525 bool su;
2526
2527 id = td->td_tid;
2528 uq = td->td_umtxq;
2529 if ((error = umtx_key_get(m, (flags & UMUTEX_ROBUST) != 0 ?
2530 TYPE_PP_ROBUST_UMUTEX : TYPE_PP_UMUTEX, GET_SHARE(flags),
2531 &uq->uq_key)) != 0)
2532 return (error);
2533
2534 if (timeout != NULL)
2535 umtx_abs_timeout_init2(&timo, timeout);
2536
2537 su = (priv_check(td, PRIV_SCHED_RTPRIO) == 0);
2538 for (;;) {
2539 old_inherited_pri = uq->uq_inherited_pri;
2540 umtxq_lock(&uq->uq_key);
2541 umtxq_busy(&uq->uq_key);
2542 umtxq_unlock(&uq->uq_key);
2543
2544 rv = fueword32(&m->m_ceilings[0], &ceiling);
2545 if (rv == -1) {
2546 error = EFAULT;
2547 goto out;
2548 }
2549 ceiling = RTP_PRIO_MAX - ceiling;
2550 if (ceiling > RTP_PRIO_MAX) {
2551 error = EINVAL;
2552 goto out;
2553 }
2554 new_pri = PRI_MIN_REALTIME + ceiling;
2555
2556 if (td->td_base_user_pri < new_pri) {
2557 error = EINVAL;
2558 goto out;
2559 }
2560 if (su) {
2561 mtx_lock(&umtx_lock);
2562 if (new_pri < uq->uq_inherited_pri) {
2563 uq->uq_inherited_pri = new_pri;
2564 thread_lock(td);
2565 if (new_pri < UPRI(td))
2566 sched_lend_user_prio(td, new_pri);
2567 thread_unlock(td);
2568 }
2569 mtx_unlock(&umtx_lock);
2570 }
2571
2572 rv = casueword32(&m->m_owner, UMUTEX_CONTESTED, &owner,
2573 id | UMUTEX_CONTESTED);
2574 /* The address was invalid. */
2575 if (rv == -1) {
2576 error = EFAULT;
2577 break;
2578 }
2579 if (rv == 0) {
2580 MPASS(owner == UMUTEX_CONTESTED);
2581 error = 0;
2582 break;
2583 }
2584 /* rv == 1 */
2585 if (owner == UMUTEX_RB_OWNERDEAD) {
2586 rv = casueword32(&m->m_owner, UMUTEX_RB_OWNERDEAD,
2587 &owner, id | UMUTEX_CONTESTED);
2588 if (rv == -1) {
2589 error = EFAULT;
2590 break;
2591 }
2592 if (rv == 0) {
2593 MPASS(owner == UMUTEX_RB_OWNERDEAD);
2594 error = EOWNERDEAD; /* success */
2595 break;
2596 }
2597
2598 /*
2599 * rv == 1, only check for suspension if we
2600 * did not already catched a signal. If we
2601 * get an error from the check, the same
2602 * condition is checked by the umtxq_sleep()
2603 * call below, so we should obliterate the
2604 * error to not skip the last loop iteration.
2605 */
2606 if (error == 0) {
2607 error = thread_check_susp(td, false);
2608 if (error == 0 && try == 0) {
2609 umtxq_unbusy_unlocked(&uq->uq_key);
2610 continue;
2611 }
2612 error = 0;
2613 }
2614 } else if (owner == UMUTEX_RB_NOTRECOV) {
2615 error = ENOTRECOVERABLE;
2616 }
2617
2618 if (try != 0)
2619 error = EBUSY;
2620
2621 /*
2622 * If we caught a signal, we have retried and now
2623 * exit immediately.
2624 */
2625 if (error != 0)
2626 break;
2627
2628 umtxq_lock(&uq->uq_key);
2629 umtxq_insert(uq);
2630 umtxq_unbusy(&uq->uq_key);
2631 error = umtxq_sleep(uq, "umtxpp", timeout == NULL ?
2632 NULL : &timo);
2633 umtxq_remove(uq);
2634 umtxq_unlock(&uq->uq_key);
2635
2636 mtx_lock(&umtx_lock);
2637 uq->uq_inherited_pri = old_inherited_pri;
2638 pri = PRI_MAX;
2639 TAILQ_FOREACH(pi, &uq->uq_pi_contested, pi_link) {
2640 uq2 = TAILQ_FIRST(&pi->pi_blocked);
2641 if (uq2 != NULL) {
2642 if (pri > UPRI(uq2->uq_thread))
2643 pri = UPRI(uq2->uq_thread);
2644 }
2645 }
2646 if (pri > uq->uq_inherited_pri)
2647 pri = uq->uq_inherited_pri;
2648 thread_lock(td);
2649 sched_lend_user_prio(td, pri);
2650 thread_unlock(td);
2651 mtx_unlock(&umtx_lock);
2652 }
2653
2654 if (error != 0 && error != EOWNERDEAD) {
2655 mtx_lock(&umtx_lock);
2656 uq->uq_inherited_pri = old_inherited_pri;
2657 pri = PRI_MAX;
2658 TAILQ_FOREACH(pi, &uq->uq_pi_contested, pi_link) {
2659 uq2 = TAILQ_FIRST(&pi->pi_blocked);
2660 if (uq2 != NULL) {
2661 if (pri > UPRI(uq2->uq_thread))
2662 pri = UPRI(uq2->uq_thread);
2663 }
2664 }
2665 if (pri > uq->uq_inherited_pri)
2666 pri = uq->uq_inherited_pri;
2667 thread_lock(td);
2668 sched_lend_user_prio(td, pri);
2669 thread_unlock(td);
2670 mtx_unlock(&umtx_lock);
2671 }
2672
2673 out:
2674 umtxq_unbusy_unlocked(&uq->uq_key);
2675 umtx_key_release(&uq->uq_key);
2676 return (error);
2677 }
2678
2679 /*
2680 * Unlock a PP mutex.
2681 */
2682 static int
do_unlock_pp(struct thread * td,struct umutex * m,uint32_t flags,bool rb)2683 do_unlock_pp(struct thread *td, struct umutex *m, uint32_t flags, bool rb)
2684 {
2685 struct umtx_key key;
2686 struct umtx_q *uq, *uq2;
2687 struct umtx_pi *pi;
2688 uint32_t id, owner, rceiling;
2689 int error, pri, new_inherited_pri;
2690 bool su;
2691
2692 id = td->td_tid;
2693 uq = td->td_umtxq;
2694 su = (priv_check(td, PRIV_SCHED_RTPRIO) == 0);
2695
2696 /*
2697 * Make sure we own this mtx.
2698 */
2699 error = fueword32(&m->m_owner, &owner);
2700 if (error == -1)
2701 return (EFAULT);
2702
2703 if ((owner & ~UMUTEX_CONTESTED) != id)
2704 return (EPERM);
2705
2706 error = copyin(&m->m_ceilings[1], &rceiling, sizeof(uint32_t));
2707 if (error != 0)
2708 return (error);
2709
2710 if (rceiling == -1)
2711 new_inherited_pri = PRI_MAX;
2712 else {
2713 rceiling = RTP_PRIO_MAX - rceiling;
2714 if (rceiling > RTP_PRIO_MAX)
2715 return (EINVAL);
2716 new_inherited_pri = PRI_MIN_REALTIME + rceiling;
2717 }
2718
2719 if ((error = umtx_key_get(m, (flags & UMUTEX_ROBUST) != 0 ?
2720 TYPE_PP_ROBUST_UMUTEX : TYPE_PP_UMUTEX, GET_SHARE(flags),
2721 &key)) != 0)
2722 return (error);
2723 umtxq_lock(&key);
2724 umtxq_busy(&key);
2725 umtxq_unlock(&key);
2726 /*
2727 * For priority protected mutex, always set unlocked state
2728 * to UMUTEX_CONTESTED, so that userland always enters kernel
2729 * to lock the mutex, it is necessary because thread priority
2730 * has to be adjusted for such mutex.
2731 */
2732 error = suword32(&m->m_owner, umtx_unlock_val(flags, rb) |
2733 UMUTEX_CONTESTED);
2734
2735 umtxq_lock(&key);
2736 if (error == 0)
2737 umtxq_signal(&key, 1);
2738 umtxq_unbusy(&key);
2739 umtxq_unlock(&key);
2740
2741 if (error == -1)
2742 error = EFAULT;
2743 else {
2744 mtx_lock(&umtx_lock);
2745 if (su || new_inherited_pri == PRI_MAX)
2746 uq->uq_inherited_pri = new_inherited_pri;
2747 pri = PRI_MAX;
2748 TAILQ_FOREACH(pi, &uq->uq_pi_contested, pi_link) {
2749 uq2 = TAILQ_FIRST(&pi->pi_blocked);
2750 if (uq2 != NULL) {
2751 if (pri > UPRI(uq2->uq_thread))
2752 pri = UPRI(uq2->uq_thread);
2753 }
2754 }
2755 if (pri > uq->uq_inherited_pri)
2756 pri = uq->uq_inherited_pri;
2757 thread_lock(td);
2758 sched_lend_user_prio(td, pri);
2759 thread_unlock(td);
2760 mtx_unlock(&umtx_lock);
2761 }
2762 umtx_key_release(&key);
2763 return (error);
2764 }
2765
2766 static int
do_set_ceiling(struct thread * td,struct umutex * m,uint32_t ceiling,uint32_t * old_ceiling)2767 do_set_ceiling(struct thread *td, struct umutex *m, uint32_t ceiling,
2768 uint32_t *old_ceiling)
2769 {
2770 struct umtx_q *uq;
2771 uint32_t flags, id, owner, save_ceiling;
2772 int error, rv, rv1;
2773
2774 error = fueword32(&m->m_flags, &flags);
2775 if (error == -1)
2776 return (EFAULT);
2777 if ((flags & UMUTEX_PRIO_PROTECT) == 0)
2778 return (EINVAL);
2779 if (ceiling > RTP_PRIO_MAX)
2780 return (EINVAL);
2781 id = td->td_tid;
2782 uq = td->td_umtxq;
2783 if ((error = umtx_key_get(m, (flags & UMUTEX_ROBUST) != 0 ?
2784 TYPE_PP_ROBUST_UMUTEX : TYPE_PP_UMUTEX, GET_SHARE(flags),
2785 &uq->uq_key)) != 0)
2786 return (error);
2787 for (;;) {
2788 umtxq_lock(&uq->uq_key);
2789 umtxq_busy(&uq->uq_key);
2790 umtxq_unlock(&uq->uq_key);
2791
2792 rv = fueword32(&m->m_ceilings[0], &save_ceiling);
2793 if (rv == -1) {
2794 error = EFAULT;
2795 break;
2796 }
2797
2798 rv = casueword32(&m->m_owner, UMUTEX_CONTESTED, &owner,
2799 id | UMUTEX_CONTESTED);
2800 if (rv == -1) {
2801 error = EFAULT;
2802 break;
2803 }
2804
2805 if (rv == 0) {
2806 MPASS(owner == UMUTEX_CONTESTED);
2807 rv = suword32(&m->m_ceilings[0], ceiling);
2808 rv1 = suword32(&m->m_owner, UMUTEX_CONTESTED);
2809 error = (rv == 0 && rv1 == 0) ? 0: EFAULT;
2810 break;
2811 }
2812
2813 if ((owner & ~UMUTEX_CONTESTED) == id) {
2814 rv = suword32(&m->m_ceilings[0], ceiling);
2815 error = rv == 0 ? 0 : EFAULT;
2816 break;
2817 }
2818
2819 if (owner == UMUTEX_RB_OWNERDEAD) {
2820 error = EOWNERDEAD;
2821 break;
2822 } else if (owner == UMUTEX_RB_NOTRECOV) {
2823 error = ENOTRECOVERABLE;
2824 break;
2825 }
2826
2827 /*
2828 * If we caught a signal, we have retried and now
2829 * exit immediately.
2830 */
2831 if (error != 0)
2832 break;
2833
2834 /*
2835 * We set the contested bit, sleep. Otherwise the lock changed
2836 * and we need to retry or we lost a race to the thread
2837 * unlocking the umtx.
2838 */
2839 umtxq_lock(&uq->uq_key);
2840 umtxq_insert(uq);
2841 umtxq_unbusy(&uq->uq_key);
2842 error = umtxq_sleep(uq, "umtxpp", NULL);
2843 umtxq_remove(uq);
2844 umtxq_unlock(&uq->uq_key);
2845 }
2846 umtxq_lock(&uq->uq_key);
2847 if (error == 0)
2848 umtxq_signal(&uq->uq_key, INT_MAX);
2849 umtxq_unbusy(&uq->uq_key);
2850 umtxq_unlock(&uq->uq_key);
2851 umtx_key_release(&uq->uq_key);
2852 if (error == 0 && old_ceiling != NULL) {
2853 rv = suword32(old_ceiling, save_ceiling);
2854 error = rv == 0 ? 0 : EFAULT;
2855 }
2856 return (error);
2857 }
2858
2859 /*
2860 * Lock a userland POSIX mutex.
2861 */
2862 static int
do_lock_umutex(struct thread * td,struct umutex * m,struct _umtx_time * timeout,int mode)2863 do_lock_umutex(struct thread *td, struct umutex *m,
2864 struct _umtx_time *timeout, int mode)
2865 {
2866 uint32_t flags;
2867 int error;
2868
2869 error = fueword32(&m->m_flags, &flags);
2870 if (error == -1)
2871 return (EFAULT);
2872
2873 switch (flags & (UMUTEX_PRIO_INHERIT | UMUTEX_PRIO_PROTECT)) {
2874 case 0:
2875 error = do_lock_normal(td, m, flags, timeout, mode);
2876 break;
2877 case UMUTEX_PRIO_INHERIT:
2878 error = do_lock_pi(td, m, flags, timeout, mode);
2879 break;
2880 case UMUTEX_PRIO_PROTECT:
2881 error = do_lock_pp(td, m, flags, timeout, mode);
2882 break;
2883 default:
2884 return (EINVAL);
2885 }
2886 if (timeout == NULL) {
2887 if (error == EINTR && mode != _UMUTEX_WAIT)
2888 error = ERESTART;
2889 } else {
2890 /* Timed-locking is not restarted. */
2891 if (error == ERESTART)
2892 error = EINTR;
2893 }
2894 return (error);
2895 }
2896
2897 /*
2898 * Unlock a userland POSIX mutex.
2899 */
2900 static int
do_unlock_umutex(struct thread * td,struct umutex * m,bool rb)2901 do_unlock_umutex(struct thread *td, struct umutex *m, bool rb)
2902 {
2903 uint32_t flags;
2904 int error;
2905
2906 error = fueword32(&m->m_flags, &flags);
2907 if (error == -1)
2908 return (EFAULT);
2909
2910 switch (flags & (UMUTEX_PRIO_INHERIT | UMUTEX_PRIO_PROTECT)) {
2911 case 0:
2912 return (do_unlock_normal(td, m, flags, rb));
2913 case UMUTEX_PRIO_INHERIT:
2914 return (do_unlock_pi(td, m, flags, rb));
2915 case UMUTEX_PRIO_PROTECT:
2916 return (do_unlock_pp(td, m, flags, rb));
2917 }
2918
2919 return (EINVAL);
2920 }
2921
2922 static int
do_cv_wait(struct thread * td,struct ucond * cv,struct umutex * m,struct timespec * timeout,u_long wflags)2923 do_cv_wait(struct thread *td, struct ucond *cv, struct umutex *m,
2924 struct timespec *timeout, u_long wflags)
2925 {
2926 struct umtx_abs_timeout timo;
2927 struct umtx_q *uq;
2928 uint32_t flags, clockid, hasw;
2929 int error;
2930
2931 uq = td->td_umtxq;
2932 error = fueword32(&cv->c_flags, &flags);
2933 if (error == -1)
2934 return (EFAULT);
2935 error = umtx_key_get(cv, TYPE_CV, GET_SHARE(flags), &uq->uq_key);
2936 if (error != 0)
2937 return (error);
2938
2939 if ((wflags & CVWAIT_CLOCKID) != 0) {
2940 error = fueword32(&cv->c_clockid, &clockid);
2941 if (error == -1) {
2942 umtx_key_release(&uq->uq_key);
2943 return (EFAULT);
2944 }
2945 if (clockid < CLOCK_REALTIME ||
2946 clockid >= CLOCK_THREAD_CPUTIME_ID) {
2947 /* hmm, only HW clock id will work. */
2948 umtx_key_release(&uq->uq_key);
2949 return (EINVAL);
2950 }
2951 } else {
2952 clockid = CLOCK_REALTIME;
2953 }
2954
2955 umtxq_lock(&uq->uq_key);
2956 umtxq_busy(&uq->uq_key);
2957 umtxq_insert(uq);
2958 umtxq_unlock(&uq->uq_key);
2959
2960 /*
2961 * Set c_has_waiters to 1 before releasing user mutex, also
2962 * don't modify cache line when unnecessary.
2963 */
2964 error = fueword32(&cv->c_has_waiters, &hasw);
2965 if (error == 0 && hasw == 0)
2966 error = suword32(&cv->c_has_waiters, 1);
2967 if (error != 0) {
2968 umtxq_lock(&uq->uq_key);
2969 umtxq_remove(uq);
2970 umtxq_unbusy(&uq->uq_key);
2971 error = EFAULT;
2972 goto out;
2973 }
2974
2975 umtxq_unbusy_unlocked(&uq->uq_key);
2976
2977 error = do_unlock_umutex(td, m, false);
2978
2979 if (timeout != NULL)
2980 umtx_abs_timeout_init(&timo, clockid,
2981 (wflags & CVWAIT_ABSTIME) != 0, timeout);
2982
2983 umtxq_lock(&uq->uq_key);
2984 if (error == 0) {
2985 error = umtxq_sleep(uq, "ucond", timeout == NULL ?
2986 NULL : &timo);
2987 }
2988
2989 if ((uq->uq_flags & UQF_UMTXQ) == 0)
2990 error = 0;
2991 else {
2992 /*
2993 * This must be timeout,interrupted by signal or
2994 * surprious wakeup, clear c_has_waiter flag when
2995 * necessary.
2996 */
2997 umtxq_busy(&uq->uq_key);
2998 if ((uq->uq_flags & UQF_UMTXQ) != 0) {
2999 int oldlen = uq->uq_cur_queue->length;
3000 umtxq_remove(uq);
3001 if (oldlen == 1) {
3002 umtxq_unlock(&uq->uq_key);
3003 if (suword32(&cv->c_has_waiters, 0) != 0 &&
3004 error == 0)
3005 error = EFAULT;
3006 umtxq_lock(&uq->uq_key);
3007 }
3008 }
3009 umtxq_unbusy(&uq->uq_key);
3010 if (error == ERESTART)
3011 error = EINTR;
3012 }
3013 out:
3014 umtxq_unlock(&uq->uq_key);
3015 umtx_key_release(&uq->uq_key);
3016 return (error);
3017 }
3018
3019 /*
3020 * Signal a userland condition variable.
3021 */
3022 static int
do_cv_signal(struct thread * td,struct ucond * cv)3023 do_cv_signal(struct thread *td, struct ucond *cv)
3024 {
3025 struct umtx_key key;
3026 int error, cnt, nwake;
3027 uint32_t flags;
3028
3029 error = fueword32(&cv->c_flags, &flags);
3030 if (error == -1)
3031 return (EFAULT);
3032 if ((error = umtx_key_get(cv, TYPE_CV, GET_SHARE(flags), &key)) != 0)
3033 return (error);
3034 umtxq_lock(&key);
3035 umtxq_busy(&key);
3036 cnt = umtxq_count(&key);
3037 nwake = umtxq_signal(&key, 1);
3038 if (cnt <= nwake) {
3039 umtxq_unlock(&key);
3040 error = suword32(&cv->c_has_waiters, 0);
3041 if (error == -1)
3042 error = EFAULT;
3043 umtxq_lock(&key);
3044 }
3045 umtxq_unbusy(&key);
3046 umtxq_unlock(&key);
3047 umtx_key_release(&key);
3048 return (error);
3049 }
3050
3051 static int
do_cv_broadcast(struct thread * td,struct ucond * cv)3052 do_cv_broadcast(struct thread *td, struct ucond *cv)
3053 {
3054 struct umtx_key key;
3055 int error;
3056 uint32_t flags;
3057
3058 error = fueword32(&cv->c_flags, &flags);
3059 if (error == -1)
3060 return (EFAULT);
3061 if ((error = umtx_key_get(cv, TYPE_CV, GET_SHARE(flags), &key)) != 0)
3062 return (error);
3063
3064 umtxq_lock(&key);
3065 umtxq_busy(&key);
3066 umtxq_signal(&key, INT_MAX);
3067 umtxq_unlock(&key);
3068
3069 error = suword32(&cv->c_has_waiters, 0);
3070 if (error == -1)
3071 error = EFAULT;
3072
3073 umtxq_unbusy_unlocked(&key);
3074
3075 umtx_key_release(&key);
3076 return (error);
3077 }
3078
3079 static int
do_rw_rdlock(struct thread * td,struct urwlock * rwlock,long fflag,struct _umtx_time * timeout)3080 do_rw_rdlock(struct thread *td, struct urwlock *rwlock, long fflag,
3081 struct _umtx_time *timeout)
3082 {
3083 struct umtx_abs_timeout timo;
3084 struct umtx_q *uq;
3085 uint32_t flags, wrflags;
3086 int32_t state, oldstate;
3087 int32_t blocked_readers;
3088 int error, error1, rv;
3089
3090 uq = td->td_umtxq;
3091 error = fueword32(&rwlock->rw_flags, &flags);
3092 if (error == -1)
3093 return (EFAULT);
3094 error = umtx_key_get(rwlock, TYPE_RWLOCK, GET_SHARE(flags), &uq->uq_key);
3095 if (error != 0)
3096 return (error);
3097
3098 if (timeout != NULL)
3099 umtx_abs_timeout_init2(&timo, timeout);
3100
3101 wrflags = URWLOCK_WRITE_OWNER;
3102 if (!(fflag & URWLOCK_PREFER_READER) && !(flags & URWLOCK_PREFER_READER))
3103 wrflags |= URWLOCK_WRITE_WAITERS;
3104
3105 for (;;) {
3106 rv = fueword32(&rwlock->rw_state, &state);
3107 if (rv == -1) {
3108 umtx_key_release(&uq->uq_key);
3109 return (EFAULT);
3110 }
3111
3112 /* try to lock it */
3113 while (!(state & wrflags)) {
3114 if (__predict_false(URWLOCK_READER_COUNT(state) ==
3115 URWLOCK_MAX_READERS)) {
3116 umtx_key_release(&uq->uq_key);
3117 return (EAGAIN);
3118 }
3119 rv = casueword32(&rwlock->rw_state, state,
3120 &oldstate, state + 1);
3121 if (rv == -1) {
3122 umtx_key_release(&uq->uq_key);
3123 return (EFAULT);
3124 }
3125 if (rv == 0) {
3126 MPASS(oldstate == state);
3127 umtx_key_release(&uq->uq_key);
3128 return (0);
3129 }
3130 error = thread_check_susp(td, true);
3131 if (error != 0)
3132 break;
3133 state = oldstate;
3134 }
3135
3136 if (error)
3137 break;
3138
3139 /* grab monitor lock */
3140 umtxq_lock(&uq->uq_key);
3141 umtxq_busy(&uq->uq_key);
3142 umtxq_unlock(&uq->uq_key);
3143
3144 /*
3145 * re-read the state, in case it changed between the try-lock above
3146 * and the check below
3147 */
3148 rv = fueword32(&rwlock->rw_state, &state);
3149 if (rv == -1)
3150 error = EFAULT;
3151
3152 /* set read contention bit */
3153 while (error == 0 && (state & wrflags) &&
3154 !(state & URWLOCK_READ_WAITERS)) {
3155 rv = casueword32(&rwlock->rw_state, state,
3156 &oldstate, state | URWLOCK_READ_WAITERS);
3157 if (rv == -1) {
3158 error = EFAULT;
3159 break;
3160 }
3161 if (rv == 0) {
3162 MPASS(oldstate == state);
3163 goto sleep;
3164 }
3165 state = oldstate;
3166 error = thread_check_susp(td, false);
3167 if (error != 0)
3168 break;
3169 }
3170 if (error != 0) {
3171 umtxq_unbusy_unlocked(&uq->uq_key);
3172 break;
3173 }
3174
3175 /* state is changed while setting flags, restart */
3176 if (!(state & wrflags)) {
3177 umtxq_unbusy_unlocked(&uq->uq_key);
3178 error = thread_check_susp(td, true);
3179 if (error != 0)
3180 break;
3181 continue;
3182 }
3183
3184 sleep:
3185 /*
3186 * Contention bit is set, before sleeping, increase
3187 * read waiter count.
3188 */
3189 rv = fueword32(&rwlock->rw_blocked_readers,
3190 &blocked_readers);
3191 if (rv == 0)
3192 rv = suword32(&rwlock->rw_blocked_readers,
3193 blocked_readers + 1);
3194 if (rv == -1) {
3195 umtxq_unbusy_unlocked(&uq->uq_key);
3196 error = EFAULT;
3197 break;
3198 }
3199
3200 while (state & wrflags) {
3201 umtxq_lock(&uq->uq_key);
3202 umtxq_insert(uq);
3203 umtxq_unbusy(&uq->uq_key);
3204
3205 error = umtxq_sleep(uq, "urdlck", timeout == NULL ?
3206 NULL : &timo);
3207
3208 umtxq_busy(&uq->uq_key);
3209 umtxq_remove(uq);
3210 umtxq_unlock(&uq->uq_key);
3211 if (error)
3212 break;
3213 rv = fueword32(&rwlock->rw_state, &state);
3214 if (rv == -1) {
3215 error = EFAULT;
3216 break;
3217 }
3218 }
3219
3220 /* decrease read waiter count, and may clear read contention bit */
3221 rv = fueword32(&rwlock->rw_blocked_readers,
3222 &blocked_readers);
3223 if (rv == 0)
3224 rv = suword32(&rwlock->rw_blocked_readers,
3225 blocked_readers - 1);
3226 if (rv == -1) {
3227 umtxq_unbusy_unlocked(&uq->uq_key);
3228 error = EFAULT;
3229 break;
3230 }
3231 if (blocked_readers == 1) {
3232 rv = fueword32(&rwlock->rw_state, &state);
3233 if (rv == -1) {
3234 umtxq_unbusy_unlocked(&uq->uq_key);
3235 error = EFAULT;
3236 break;
3237 }
3238 for (;;) {
3239 rv = casueword32(&rwlock->rw_state, state,
3240 &oldstate, state & ~URWLOCK_READ_WAITERS);
3241 if (rv == -1) {
3242 error = EFAULT;
3243 break;
3244 }
3245 if (rv == 0) {
3246 MPASS(oldstate == state);
3247 break;
3248 }
3249 state = oldstate;
3250 error1 = thread_check_susp(td, false);
3251 if (error1 != 0) {
3252 if (error == 0)
3253 error = error1;
3254 break;
3255 }
3256 }
3257 }
3258
3259 umtxq_unbusy_unlocked(&uq->uq_key);
3260 if (error != 0)
3261 break;
3262 }
3263 umtx_key_release(&uq->uq_key);
3264 if (error == ERESTART)
3265 error = EINTR;
3266 return (error);
3267 }
3268
3269 static int
do_rw_wrlock(struct thread * td,struct urwlock * rwlock,struct _umtx_time * timeout)3270 do_rw_wrlock(struct thread *td, struct urwlock *rwlock, struct _umtx_time *timeout)
3271 {
3272 struct umtx_abs_timeout timo;
3273 struct umtx_q *uq;
3274 uint32_t flags;
3275 int32_t state, oldstate;
3276 int32_t blocked_writers;
3277 int32_t blocked_readers;
3278 int error, error1, rv;
3279
3280 uq = td->td_umtxq;
3281 error = fueword32(&rwlock->rw_flags, &flags);
3282 if (error == -1)
3283 return (EFAULT);
3284 error = umtx_key_get(rwlock, TYPE_RWLOCK, GET_SHARE(flags), &uq->uq_key);
3285 if (error != 0)
3286 return (error);
3287
3288 if (timeout != NULL)
3289 umtx_abs_timeout_init2(&timo, timeout);
3290
3291 blocked_readers = 0;
3292 for (;;) {
3293 rv = fueword32(&rwlock->rw_state, &state);
3294 if (rv == -1) {
3295 umtx_key_release(&uq->uq_key);
3296 return (EFAULT);
3297 }
3298 while ((state & URWLOCK_WRITE_OWNER) == 0 &&
3299 URWLOCK_READER_COUNT(state) == 0) {
3300 rv = casueword32(&rwlock->rw_state, state,
3301 &oldstate, state | URWLOCK_WRITE_OWNER);
3302 if (rv == -1) {
3303 umtx_key_release(&uq->uq_key);
3304 return (EFAULT);
3305 }
3306 if (rv == 0) {
3307 MPASS(oldstate == state);
3308 umtx_key_release(&uq->uq_key);
3309 return (0);
3310 }
3311 state = oldstate;
3312 error = thread_check_susp(td, true);
3313 if (error != 0)
3314 break;
3315 }
3316
3317 if (error) {
3318 if ((state & (URWLOCK_WRITE_OWNER |
3319 URWLOCK_WRITE_WAITERS)) == 0 &&
3320 blocked_readers != 0) {
3321 umtxq_lock(&uq->uq_key);
3322 umtxq_busy(&uq->uq_key);
3323 umtxq_signal_queue(&uq->uq_key, INT_MAX,
3324 UMTX_SHARED_QUEUE);
3325 umtxq_unbusy(&uq->uq_key);
3326 umtxq_unlock(&uq->uq_key);
3327 }
3328
3329 break;
3330 }
3331
3332 /* grab monitor lock */
3333 umtxq_lock(&uq->uq_key);
3334 umtxq_busy(&uq->uq_key);
3335 umtxq_unlock(&uq->uq_key);
3336
3337 /*
3338 * Re-read the state, in case it changed between the
3339 * try-lock above and the check below.
3340 */
3341 rv = fueword32(&rwlock->rw_state, &state);
3342 if (rv == -1)
3343 error = EFAULT;
3344
3345 while (error == 0 && ((state & URWLOCK_WRITE_OWNER) ||
3346 URWLOCK_READER_COUNT(state) != 0) &&
3347 (state & URWLOCK_WRITE_WAITERS) == 0) {
3348 rv = casueword32(&rwlock->rw_state, state,
3349 &oldstate, state | URWLOCK_WRITE_WAITERS);
3350 if (rv == -1) {
3351 error = EFAULT;
3352 break;
3353 }
3354 if (rv == 0) {
3355 MPASS(oldstate == state);
3356 goto sleep;
3357 }
3358 state = oldstate;
3359 error = thread_check_susp(td, false);
3360 if (error != 0)
3361 break;
3362 }
3363 if (error != 0) {
3364 umtxq_unbusy_unlocked(&uq->uq_key);
3365 break;
3366 }
3367
3368 if ((state & URWLOCK_WRITE_OWNER) == 0 &&
3369 URWLOCK_READER_COUNT(state) == 0) {
3370 umtxq_unbusy_unlocked(&uq->uq_key);
3371 error = thread_check_susp(td, false);
3372 if (error != 0)
3373 break;
3374 continue;
3375 }
3376 sleep:
3377 rv = fueword32(&rwlock->rw_blocked_writers,
3378 &blocked_writers);
3379 if (rv == 0)
3380 rv = suword32(&rwlock->rw_blocked_writers,
3381 blocked_writers + 1);
3382 if (rv == -1) {
3383 umtxq_unbusy_unlocked(&uq->uq_key);
3384 error = EFAULT;
3385 break;
3386 }
3387
3388 while ((state & URWLOCK_WRITE_OWNER) ||
3389 URWLOCK_READER_COUNT(state) != 0) {
3390 umtxq_lock(&uq->uq_key);
3391 umtxq_insert_queue(uq, UMTX_EXCLUSIVE_QUEUE);
3392 umtxq_unbusy(&uq->uq_key);
3393
3394 error = umtxq_sleep(uq, "uwrlck", timeout == NULL ?
3395 NULL : &timo);
3396
3397 umtxq_busy(&uq->uq_key);
3398 umtxq_remove_queue(uq, UMTX_EXCLUSIVE_QUEUE);
3399 umtxq_unlock(&uq->uq_key);
3400 if (error)
3401 break;
3402 rv = fueword32(&rwlock->rw_state, &state);
3403 if (rv == -1) {
3404 error = EFAULT;
3405 break;
3406 }
3407 }
3408
3409 rv = fueword32(&rwlock->rw_blocked_writers,
3410 &blocked_writers);
3411 if (rv == 0)
3412 rv = suword32(&rwlock->rw_blocked_writers,
3413 blocked_writers - 1);
3414 if (rv == -1) {
3415 umtxq_unbusy_unlocked(&uq->uq_key);
3416 error = EFAULT;
3417 break;
3418 }
3419 if (blocked_writers == 1) {
3420 rv = fueword32(&rwlock->rw_state, &state);
3421 if (rv == -1) {
3422 umtxq_unbusy_unlocked(&uq->uq_key);
3423 error = EFAULT;
3424 break;
3425 }
3426 for (;;) {
3427 rv = casueword32(&rwlock->rw_state, state,
3428 &oldstate, state & ~URWLOCK_WRITE_WAITERS);
3429 if (rv == -1) {
3430 error = EFAULT;
3431 break;
3432 }
3433 if (rv == 0) {
3434 MPASS(oldstate == state);
3435 break;
3436 }
3437 state = oldstate;
3438 error1 = thread_check_susp(td, false);
3439 /*
3440 * We are leaving the URWLOCK_WRITE_WAITERS
3441 * behind, but this should not harm the
3442 * correctness.
3443 */
3444 if (error1 != 0) {
3445 if (error == 0)
3446 error = error1;
3447 break;
3448 }
3449 }
3450 rv = fueword32(&rwlock->rw_blocked_readers,
3451 &blocked_readers);
3452 if (rv == -1) {
3453 umtxq_unbusy_unlocked(&uq->uq_key);
3454 error = EFAULT;
3455 break;
3456 }
3457 } else
3458 blocked_readers = 0;
3459
3460 umtxq_unbusy_unlocked(&uq->uq_key);
3461 }
3462
3463 umtx_key_release(&uq->uq_key);
3464 if (error == ERESTART)
3465 error = EINTR;
3466 return (error);
3467 }
3468
3469 static int
do_rw_unlock(struct thread * td,struct urwlock * rwlock)3470 do_rw_unlock(struct thread *td, struct urwlock *rwlock)
3471 {
3472 struct umtx_q *uq;
3473 uint32_t flags;
3474 int32_t state, oldstate;
3475 int error, rv, q, count;
3476
3477 uq = td->td_umtxq;
3478 error = fueword32(&rwlock->rw_flags, &flags);
3479 if (error == -1)
3480 return (EFAULT);
3481 error = umtx_key_get(rwlock, TYPE_RWLOCK, GET_SHARE(flags), &uq->uq_key);
3482 if (error != 0)
3483 return (error);
3484
3485 error = fueword32(&rwlock->rw_state, &state);
3486 if (error == -1) {
3487 error = EFAULT;
3488 goto out;
3489 }
3490 if (state & URWLOCK_WRITE_OWNER) {
3491 for (;;) {
3492 rv = casueword32(&rwlock->rw_state, state,
3493 &oldstate, state & ~URWLOCK_WRITE_OWNER);
3494 if (rv == -1) {
3495 error = EFAULT;
3496 goto out;
3497 }
3498 if (rv == 1) {
3499 state = oldstate;
3500 if (!(oldstate & URWLOCK_WRITE_OWNER)) {
3501 error = EPERM;
3502 goto out;
3503 }
3504 error = thread_check_susp(td, true);
3505 if (error != 0)
3506 goto out;
3507 } else
3508 break;
3509 }
3510 } else if (URWLOCK_READER_COUNT(state) != 0) {
3511 for (;;) {
3512 rv = casueword32(&rwlock->rw_state, state,
3513 &oldstate, state - 1);
3514 if (rv == -1) {
3515 error = EFAULT;
3516 goto out;
3517 }
3518 if (rv == 1) {
3519 state = oldstate;
3520 if (URWLOCK_READER_COUNT(oldstate) == 0) {
3521 error = EPERM;
3522 goto out;
3523 }
3524 error = thread_check_susp(td, true);
3525 if (error != 0)
3526 goto out;
3527 } else
3528 break;
3529 }
3530 } else {
3531 error = EPERM;
3532 goto out;
3533 }
3534
3535 count = 0;
3536
3537 if (!(flags & URWLOCK_PREFER_READER)) {
3538 if (state & URWLOCK_WRITE_WAITERS) {
3539 count = 1;
3540 q = UMTX_EXCLUSIVE_QUEUE;
3541 } else if (state & URWLOCK_READ_WAITERS) {
3542 count = INT_MAX;
3543 q = UMTX_SHARED_QUEUE;
3544 }
3545 } else {
3546 if (state & URWLOCK_READ_WAITERS) {
3547 count = INT_MAX;
3548 q = UMTX_SHARED_QUEUE;
3549 } else if (state & URWLOCK_WRITE_WAITERS) {
3550 count = 1;
3551 q = UMTX_EXCLUSIVE_QUEUE;
3552 }
3553 }
3554
3555 if (count) {
3556 umtxq_lock(&uq->uq_key);
3557 umtxq_busy(&uq->uq_key);
3558 umtxq_signal_queue(&uq->uq_key, count, q);
3559 umtxq_unbusy(&uq->uq_key);
3560 umtxq_unlock(&uq->uq_key);
3561 }
3562 out:
3563 umtx_key_release(&uq->uq_key);
3564 return (error);
3565 }
3566
3567 #if defined(COMPAT_FREEBSD9) || defined(COMPAT_FREEBSD10)
3568 static int
do_sem_wait(struct thread * td,struct _usem * sem,struct _umtx_time * timeout)3569 do_sem_wait(struct thread *td, struct _usem *sem, struct _umtx_time *timeout)
3570 {
3571 struct umtx_abs_timeout timo;
3572 struct umtx_q *uq;
3573 uint32_t flags, count, count1;
3574 int error, rv, rv1;
3575
3576 uq = td->td_umtxq;
3577 error = fueword32(&sem->_flags, &flags);
3578 if (error == -1)
3579 return (EFAULT);
3580 error = umtx_key_get(sem, TYPE_SEM, GET_SHARE(flags), &uq->uq_key);
3581 if (error != 0)
3582 return (error);
3583
3584 if (timeout != NULL)
3585 umtx_abs_timeout_init2(&timo, timeout);
3586
3587 again:
3588 umtxq_lock(&uq->uq_key);
3589 umtxq_busy(&uq->uq_key);
3590 umtxq_insert(uq);
3591 umtxq_unlock(&uq->uq_key);
3592 rv = casueword32(&sem->_has_waiters, 0, &count1, 1);
3593 if (rv != -1)
3594 rv1 = fueword32(&sem->_count, &count);
3595 if (rv == -1 || rv1 == -1 || count != 0 || (rv == 1 && count1 == 0)) {
3596 if (rv == 0)
3597 rv = suword32(&sem->_has_waiters, 0);
3598 umtxq_lock(&uq->uq_key);
3599 umtxq_unbusy(&uq->uq_key);
3600 umtxq_remove(uq);
3601 umtxq_unlock(&uq->uq_key);
3602 if (rv == -1 || rv1 == -1) {
3603 error = EFAULT;
3604 goto out;
3605 }
3606 if (count != 0) {
3607 error = 0;
3608 goto out;
3609 }
3610 MPASS(rv == 1 && count1 == 0);
3611 rv = thread_check_susp(td, true);
3612 if (rv == 0)
3613 goto again;
3614 error = rv;
3615 goto out;
3616 }
3617 umtxq_lock(&uq->uq_key);
3618 umtxq_unbusy(&uq->uq_key);
3619
3620 error = umtxq_sleep(uq, "usem", timeout == NULL ? NULL : &timo);
3621
3622 if ((uq->uq_flags & UQF_UMTXQ) == 0)
3623 error = 0;
3624 else {
3625 umtxq_remove(uq);
3626 /* A relative timeout cannot be restarted. */
3627 if (error == ERESTART && timeout != NULL &&
3628 (timeout->_flags & UMTX_ABSTIME) == 0)
3629 error = EINTR;
3630 }
3631 umtxq_unlock(&uq->uq_key);
3632 out:
3633 umtx_key_release(&uq->uq_key);
3634 return (error);
3635 }
3636
3637 /*
3638 * Signal a userland semaphore.
3639 */
3640 static int
do_sem_wake(struct thread * td,struct _usem * sem)3641 do_sem_wake(struct thread *td, struct _usem *sem)
3642 {
3643 struct umtx_key key;
3644 int error, cnt;
3645 uint32_t flags;
3646
3647 error = fueword32(&sem->_flags, &flags);
3648 if (error == -1)
3649 return (EFAULT);
3650 if ((error = umtx_key_get(sem, TYPE_SEM, GET_SHARE(flags), &key)) != 0)
3651 return (error);
3652 umtxq_lock(&key);
3653 umtxq_busy(&key);
3654 cnt = umtxq_count(&key);
3655 if (cnt > 0) {
3656 /*
3657 * Check if count is greater than 0, this means the memory is
3658 * still being referenced by user code, so we can safely
3659 * update _has_waiters flag.
3660 */
3661 if (cnt == 1) {
3662 umtxq_unlock(&key);
3663 error = suword32(&sem->_has_waiters, 0);
3664 umtxq_lock(&key);
3665 if (error == -1)
3666 error = EFAULT;
3667 }
3668 umtxq_signal(&key, 1);
3669 }
3670 umtxq_unbusy(&key);
3671 umtxq_unlock(&key);
3672 umtx_key_release(&key);
3673 return (error);
3674 }
3675 #endif
3676
3677 static int
do_sem2_wait(struct thread * td,struct _usem2 * sem,struct _umtx_time * timeout)3678 do_sem2_wait(struct thread *td, struct _usem2 *sem, struct _umtx_time *timeout)
3679 {
3680 struct umtx_abs_timeout timo;
3681 struct umtx_q *uq;
3682 uint32_t count, flags;
3683 int error, rv;
3684
3685 uq = td->td_umtxq;
3686 flags = fuword32(&sem->_flags);
3687 if (timeout != NULL)
3688 umtx_abs_timeout_init2(&timo, timeout);
3689
3690 again:
3691 error = umtx_key_get(sem, TYPE_SEM, GET_SHARE(flags), &uq->uq_key);
3692 if (error != 0)
3693 return (error);
3694 umtxq_lock(&uq->uq_key);
3695 umtxq_busy(&uq->uq_key);
3696 umtxq_insert(uq);
3697 umtxq_unlock(&uq->uq_key);
3698 rv = fueword32(&sem->_count, &count);
3699 if (rv == -1) {
3700 umtxq_lock(&uq->uq_key);
3701 umtxq_unbusy(&uq->uq_key);
3702 umtxq_remove(uq);
3703 umtxq_unlock(&uq->uq_key);
3704 umtx_key_release(&uq->uq_key);
3705 return (EFAULT);
3706 }
3707 for (;;) {
3708 if (USEM_COUNT(count) != 0) {
3709 umtxq_lock(&uq->uq_key);
3710 umtxq_unbusy(&uq->uq_key);
3711 umtxq_remove(uq);
3712 umtxq_unlock(&uq->uq_key);
3713 umtx_key_release(&uq->uq_key);
3714 return (0);
3715 }
3716 if (count == USEM_HAS_WAITERS)
3717 break;
3718 rv = casueword32(&sem->_count, 0, &count, USEM_HAS_WAITERS);
3719 if (rv == 0)
3720 break;
3721 umtxq_lock(&uq->uq_key);
3722 umtxq_unbusy(&uq->uq_key);
3723 umtxq_remove(uq);
3724 umtxq_unlock(&uq->uq_key);
3725 umtx_key_release(&uq->uq_key);
3726 if (rv == -1)
3727 return (EFAULT);
3728 rv = thread_check_susp(td, true);
3729 if (rv != 0)
3730 return (rv);
3731 goto again;
3732 }
3733 umtxq_lock(&uq->uq_key);
3734 umtxq_unbusy(&uq->uq_key);
3735
3736 error = umtxq_sleep(uq, "usem", timeout == NULL ? NULL : &timo);
3737
3738 if ((uq->uq_flags & UQF_UMTXQ) == 0)
3739 error = 0;
3740 else {
3741 umtxq_remove(uq);
3742 if (timeout != NULL && (timeout->_flags & UMTX_ABSTIME) == 0) {
3743 /* A relative timeout cannot be restarted. */
3744 if (error == ERESTART)
3745 error = EINTR;
3746 if (error == EINTR) {
3747 kern_clock_gettime(curthread, timo.clockid,
3748 &timo.cur);
3749 timespecsub(&timo.end, &timo.cur,
3750 &timeout->_timeout);
3751 }
3752 }
3753 }
3754 umtxq_unlock(&uq->uq_key);
3755 umtx_key_release(&uq->uq_key);
3756 return (error);
3757 }
3758
3759 /*
3760 * Signal a userland semaphore.
3761 */
3762 static int
do_sem2_wake(struct thread * td,struct _usem2 * sem)3763 do_sem2_wake(struct thread *td, struct _usem2 *sem)
3764 {
3765 struct umtx_key key;
3766 int error, cnt, rv;
3767 uint32_t count, flags;
3768
3769 rv = fueword32(&sem->_flags, &flags);
3770 if (rv == -1)
3771 return (EFAULT);
3772 if ((error = umtx_key_get(sem, TYPE_SEM, GET_SHARE(flags), &key)) != 0)
3773 return (error);
3774 umtxq_lock(&key);
3775 umtxq_busy(&key);
3776 cnt = umtxq_count(&key);
3777 if (cnt > 0) {
3778 /*
3779 * If this was the last sleeping thread, clear the waiters
3780 * flag in _count.
3781 */
3782 if (cnt == 1) {
3783 umtxq_unlock(&key);
3784 rv = fueword32(&sem->_count, &count);
3785 while (rv != -1 && count & USEM_HAS_WAITERS) {
3786 rv = casueword32(&sem->_count, count, &count,
3787 count & ~USEM_HAS_WAITERS);
3788 if (rv == 1) {
3789 rv = thread_check_susp(td, true);
3790 if (rv != 0)
3791 break;
3792 }
3793 }
3794 if (rv == -1)
3795 error = EFAULT;
3796 else if (rv > 0) {
3797 error = rv;
3798 }
3799 umtxq_lock(&key);
3800 }
3801
3802 umtxq_signal(&key, 1);
3803 }
3804 umtxq_unbusy(&key);
3805 umtxq_unlock(&key);
3806 umtx_key_release(&key);
3807 return (error);
3808 }
3809
3810 #ifdef COMPAT_FREEBSD10
3811 int
freebsd10__umtx_lock(struct thread * td,struct freebsd10__umtx_lock_args * uap)3812 freebsd10__umtx_lock(struct thread *td, struct freebsd10__umtx_lock_args *uap)
3813 {
3814 return (do_lock_umtx(td, uap->umtx, td->td_tid, 0));
3815 }
3816
3817 int
freebsd10__umtx_unlock(struct thread * td,struct freebsd10__umtx_unlock_args * uap)3818 freebsd10__umtx_unlock(struct thread *td,
3819 struct freebsd10__umtx_unlock_args *uap)
3820 {
3821 return (do_unlock_umtx(td, uap->umtx, td->td_tid));
3822 }
3823 #endif
3824
3825 inline int
umtx_copyin_timeout(const void * uaddr,struct timespec * tsp)3826 umtx_copyin_timeout(const void *uaddr, struct timespec *tsp)
3827 {
3828 int error;
3829
3830 error = copyin(uaddr, tsp, sizeof(*tsp));
3831 if (error == 0) {
3832 if (!timespecvalid_interval(tsp))
3833 error = EINVAL;
3834 }
3835 return (error);
3836 }
3837
3838 static inline int
umtx_copyin_umtx_time(const void * uaddr,size_t size,struct _umtx_time * tp)3839 umtx_copyin_umtx_time(const void *uaddr, size_t size, struct _umtx_time *tp)
3840 {
3841 int error;
3842
3843 if (size <= sizeof(tp->_timeout)) {
3844 tp->_clockid = CLOCK_REALTIME;
3845 tp->_flags = 0;
3846 error = copyin(uaddr, &tp->_timeout, sizeof(tp->_timeout));
3847 } else
3848 error = copyin(uaddr, tp, sizeof(*tp));
3849 if (error != 0)
3850 return (error);
3851 if (!timespecvalid_interval(&tp->_timeout))
3852 return (EINVAL);
3853 return (0);
3854 }
3855
3856 static int
umtx_copyin_robust_lists(const void * uaddr,size_t size,struct umtx_robust_lists_params * rb)3857 umtx_copyin_robust_lists(const void *uaddr, size_t size,
3858 struct umtx_robust_lists_params *rb)
3859 {
3860
3861 if (size > sizeof(*rb))
3862 return (EINVAL);
3863 return (copyin(uaddr, rb, size));
3864 }
3865
3866 static int
umtx_copyout_timeout(void * uaddr,size_t sz,struct timespec * tsp)3867 umtx_copyout_timeout(void *uaddr, size_t sz, struct timespec *tsp)
3868 {
3869
3870 /*
3871 * Should be guaranteed by the caller, sz == uaddr1 - sizeof(_umtx_time)
3872 * and we're only called if sz >= sizeof(timespec) as supplied in the
3873 * copyops.
3874 */
3875 KASSERT(sz >= sizeof(*tsp),
3876 ("umtx_copyops specifies incorrect sizes"));
3877
3878 return (copyout(tsp, uaddr, sizeof(*tsp)));
3879 }
3880
3881 #ifdef COMPAT_FREEBSD10
3882 static int
__umtx_op_lock_umtx(struct thread * td,struct _umtx_op_args * uap,const struct umtx_copyops * ops)3883 __umtx_op_lock_umtx(struct thread *td, struct _umtx_op_args *uap,
3884 const struct umtx_copyops *ops)
3885 {
3886 struct timespec *ts, timeout;
3887 int error;
3888
3889 /* Allow a null timespec (wait forever). */
3890 if (uap->uaddr2 == NULL)
3891 ts = NULL;
3892 else {
3893 error = ops->copyin_timeout(uap->uaddr2, &timeout);
3894 if (error != 0)
3895 return (error);
3896 ts = &timeout;
3897 }
3898 #ifdef COMPAT_FREEBSD32
3899 if (ops->compat32)
3900 return (do_lock_umtx32(td, uap->obj, uap->val, ts));
3901 #endif
3902 return (do_lock_umtx(td, uap->obj, uap->val, ts));
3903 }
3904
3905 static int
__umtx_op_unlock_umtx(struct thread * td,struct _umtx_op_args * uap,const struct umtx_copyops * ops)3906 __umtx_op_unlock_umtx(struct thread *td, struct _umtx_op_args *uap,
3907 const struct umtx_copyops *ops)
3908 {
3909 #ifdef COMPAT_FREEBSD32
3910 if (ops->compat32)
3911 return (do_unlock_umtx32(td, uap->obj, uap->val));
3912 #endif
3913 return (do_unlock_umtx(td, uap->obj, uap->val));
3914 }
3915 #endif /* COMPAT_FREEBSD10 */
3916
3917 #if !defined(COMPAT_FREEBSD10)
3918 static int
__umtx_op_unimpl(struct thread * td __unused,struct _umtx_op_args * uap __unused,const struct umtx_copyops * ops __unused)3919 __umtx_op_unimpl(struct thread *td __unused, struct _umtx_op_args *uap __unused,
3920 const struct umtx_copyops *ops __unused)
3921 {
3922 return (EOPNOTSUPP);
3923 }
3924 #endif /* COMPAT_FREEBSD10 */
3925
3926 static int
__umtx_op_wait(struct thread * td,struct _umtx_op_args * uap,const struct umtx_copyops * ops)3927 __umtx_op_wait(struct thread *td, struct _umtx_op_args *uap,
3928 const struct umtx_copyops *ops)
3929 {
3930 struct _umtx_time timeout, *tm_p;
3931 int error;
3932
3933 if (uap->uaddr2 == NULL)
3934 tm_p = NULL;
3935 else {
3936 error = ops->copyin_umtx_time(
3937 uap->uaddr2, (size_t)uap->uaddr1, &timeout);
3938 if (error != 0)
3939 return (error);
3940 tm_p = &timeout;
3941 }
3942 return (do_wait(td, uap->obj, uap->val, tm_p, ops->compat32, 0));
3943 }
3944
3945 static int
__umtx_op_wait_uint(struct thread * td,struct _umtx_op_args * uap,const struct umtx_copyops * ops)3946 __umtx_op_wait_uint(struct thread *td, struct _umtx_op_args *uap,
3947 const struct umtx_copyops *ops)
3948 {
3949 struct _umtx_time timeout, *tm_p;
3950 int error;
3951
3952 if (uap->uaddr2 == NULL)
3953 tm_p = NULL;
3954 else {
3955 error = ops->copyin_umtx_time(
3956 uap->uaddr2, (size_t)uap->uaddr1, &timeout);
3957 if (error != 0)
3958 return (error);
3959 tm_p = &timeout;
3960 }
3961 return (do_wait(td, uap->obj, uap->val, tm_p, 1, 0));
3962 }
3963
3964 static int
__umtx_op_wait_uint_private(struct thread * td,struct _umtx_op_args * uap,const struct umtx_copyops * ops)3965 __umtx_op_wait_uint_private(struct thread *td, struct _umtx_op_args *uap,
3966 const struct umtx_copyops *ops)
3967 {
3968 struct _umtx_time *tm_p, timeout;
3969 int error;
3970
3971 if (uap->uaddr2 == NULL)
3972 tm_p = NULL;
3973 else {
3974 error = ops->copyin_umtx_time(
3975 uap->uaddr2, (size_t)uap->uaddr1, &timeout);
3976 if (error != 0)
3977 return (error);
3978 tm_p = &timeout;
3979 }
3980 return (do_wait(td, uap->obj, uap->val, tm_p, 1, 1));
3981 }
3982
3983 static int
__umtx_op_wake(struct thread * td,struct _umtx_op_args * uap,const struct umtx_copyops * ops __unused)3984 __umtx_op_wake(struct thread *td, struct _umtx_op_args *uap,
3985 const struct umtx_copyops *ops __unused)
3986 {
3987
3988 return (kern_umtx_wake(td, uap->obj, uap->val, 0));
3989 }
3990
3991 #define BATCH_SIZE 128
3992 static int
__umtx_op_nwake_private_native(struct thread * td,struct _umtx_op_args * uap)3993 __umtx_op_nwake_private_native(struct thread *td, struct _umtx_op_args *uap)
3994 {
3995 char *uaddrs[BATCH_SIZE], **upp;
3996 int count, error, i, pos, tocopy;
3997
3998 upp = (char **)uap->obj;
3999 error = 0;
4000 for (count = uap->val, pos = 0; count > 0; count -= tocopy,
4001 pos += tocopy) {
4002 tocopy = MIN(count, BATCH_SIZE);
4003 error = copyin(upp + pos, uaddrs, tocopy * sizeof(char *));
4004 if (error != 0)
4005 break;
4006 for (i = 0; i < tocopy; ++i) {
4007 kern_umtx_wake(td, uaddrs[i], INT_MAX, 1);
4008 }
4009 maybe_yield();
4010 }
4011 return (error);
4012 }
4013
4014 static int
__umtx_op_nwake_private_compat32(struct thread * td,struct _umtx_op_args * uap)4015 __umtx_op_nwake_private_compat32(struct thread *td, struct _umtx_op_args *uap)
4016 {
4017 uint32_t uaddrs[BATCH_SIZE], *upp;
4018 int count, error, i, pos, tocopy;
4019
4020 upp = (uint32_t *)uap->obj;
4021 error = 0;
4022 for (count = uap->val, pos = 0; count > 0; count -= tocopy,
4023 pos += tocopy) {
4024 tocopy = MIN(count, BATCH_SIZE);
4025 error = copyin(upp + pos, uaddrs, tocopy * sizeof(uint32_t));
4026 if (error != 0)
4027 break;
4028 for (i = 0; i < tocopy; ++i) {
4029 kern_umtx_wake(td, (void *)(uintptr_t)uaddrs[i],
4030 INT_MAX, 1);
4031 }
4032 maybe_yield();
4033 }
4034 return (error);
4035 }
4036
4037 static int
__umtx_op_nwake_private(struct thread * td,struct _umtx_op_args * uap,const struct umtx_copyops * ops)4038 __umtx_op_nwake_private(struct thread *td, struct _umtx_op_args *uap,
4039 const struct umtx_copyops *ops)
4040 {
4041
4042 if (ops->compat32)
4043 return (__umtx_op_nwake_private_compat32(td, uap));
4044 return (__umtx_op_nwake_private_native(td, uap));
4045 }
4046
4047 static int
__umtx_op_wake_private(struct thread * td,struct _umtx_op_args * uap,const struct umtx_copyops * ops __unused)4048 __umtx_op_wake_private(struct thread *td, struct _umtx_op_args *uap,
4049 const struct umtx_copyops *ops __unused)
4050 {
4051
4052 return (kern_umtx_wake(td, uap->obj, uap->val, 1));
4053 }
4054
4055 static int
__umtx_op_lock_umutex(struct thread * td,struct _umtx_op_args * uap,const struct umtx_copyops * ops)4056 __umtx_op_lock_umutex(struct thread *td, struct _umtx_op_args *uap,
4057 const struct umtx_copyops *ops)
4058 {
4059 struct _umtx_time *tm_p, timeout;
4060 int error;
4061
4062 /* Allow a null timespec (wait forever). */
4063 if (uap->uaddr2 == NULL)
4064 tm_p = NULL;
4065 else {
4066 error = ops->copyin_umtx_time(
4067 uap->uaddr2, (size_t)uap->uaddr1, &timeout);
4068 if (error != 0)
4069 return (error);
4070 tm_p = &timeout;
4071 }
4072 return (do_lock_umutex(td, uap->obj, tm_p, 0));
4073 }
4074
4075 static int
__umtx_op_trylock_umutex(struct thread * td,struct _umtx_op_args * uap,const struct umtx_copyops * ops __unused)4076 __umtx_op_trylock_umutex(struct thread *td, struct _umtx_op_args *uap,
4077 const struct umtx_copyops *ops __unused)
4078 {
4079
4080 return (do_lock_umutex(td, uap->obj, NULL, _UMUTEX_TRY));
4081 }
4082
4083 static int
__umtx_op_wait_umutex(struct thread * td,struct _umtx_op_args * uap,const struct umtx_copyops * ops)4084 __umtx_op_wait_umutex(struct thread *td, struct _umtx_op_args *uap,
4085 const struct umtx_copyops *ops)
4086 {
4087 struct _umtx_time *tm_p, timeout;
4088 int error;
4089
4090 /* Allow a null timespec (wait forever). */
4091 if (uap->uaddr2 == NULL)
4092 tm_p = NULL;
4093 else {
4094 error = ops->copyin_umtx_time(
4095 uap->uaddr2, (size_t)uap->uaddr1, &timeout);
4096 if (error != 0)
4097 return (error);
4098 tm_p = &timeout;
4099 }
4100 return (do_lock_umutex(td, uap->obj, tm_p, _UMUTEX_WAIT));
4101 }
4102
4103 static int
__umtx_op_wake_umutex(struct thread * td,struct _umtx_op_args * uap,const struct umtx_copyops * ops __unused)4104 __umtx_op_wake_umutex(struct thread *td, struct _umtx_op_args *uap,
4105 const struct umtx_copyops *ops __unused)
4106 {
4107
4108 return (do_wake_umutex(td, uap->obj));
4109 }
4110
4111 static int
__umtx_op_unlock_umutex(struct thread * td,struct _umtx_op_args * uap,const struct umtx_copyops * ops __unused)4112 __umtx_op_unlock_umutex(struct thread *td, struct _umtx_op_args *uap,
4113 const struct umtx_copyops *ops __unused)
4114 {
4115
4116 return (do_unlock_umutex(td, uap->obj, false));
4117 }
4118
4119 static int
__umtx_op_set_ceiling(struct thread * td,struct _umtx_op_args * uap,const struct umtx_copyops * ops __unused)4120 __umtx_op_set_ceiling(struct thread *td, struct _umtx_op_args *uap,
4121 const struct umtx_copyops *ops __unused)
4122 {
4123
4124 return (do_set_ceiling(td, uap->obj, uap->val, uap->uaddr1));
4125 }
4126
4127 static int
__umtx_op_cv_wait(struct thread * td,struct _umtx_op_args * uap,const struct umtx_copyops * ops)4128 __umtx_op_cv_wait(struct thread *td, struct _umtx_op_args *uap,
4129 const struct umtx_copyops *ops)
4130 {
4131 struct timespec *ts, timeout;
4132 int error;
4133
4134 /* Allow a null timespec (wait forever). */
4135 if (uap->uaddr2 == NULL)
4136 ts = NULL;
4137 else {
4138 error = ops->copyin_timeout(uap->uaddr2, &timeout);
4139 if (error != 0)
4140 return (error);
4141 ts = &timeout;
4142 }
4143 return (do_cv_wait(td, uap->obj, uap->uaddr1, ts, uap->val));
4144 }
4145
4146 static int
__umtx_op_cv_signal(struct thread * td,struct _umtx_op_args * uap,const struct umtx_copyops * ops __unused)4147 __umtx_op_cv_signal(struct thread *td, struct _umtx_op_args *uap,
4148 const struct umtx_copyops *ops __unused)
4149 {
4150
4151 return (do_cv_signal(td, uap->obj));
4152 }
4153
4154 static int
__umtx_op_cv_broadcast(struct thread * td,struct _umtx_op_args * uap,const struct umtx_copyops * ops __unused)4155 __umtx_op_cv_broadcast(struct thread *td, struct _umtx_op_args *uap,
4156 const struct umtx_copyops *ops __unused)
4157 {
4158
4159 return (do_cv_broadcast(td, uap->obj));
4160 }
4161
4162 static int
__umtx_op_rw_rdlock(struct thread * td,struct _umtx_op_args * uap,const struct umtx_copyops * ops)4163 __umtx_op_rw_rdlock(struct thread *td, struct _umtx_op_args *uap,
4164 const struct umtx_copyops *ops)
4165 {
4166 struct _umtx_time timeout;
4167 int error;
4168
4169 /* Allow a null timespec (wait forever). */
4170 if (uap->uaddr2 == NULL) {
4171 error = do_rw_rdlock(td, uap->obj, uap->val, 0);
4172 } else {
4173 error = ops->copyin_umtx_time(uap->uaddr2,
4174 (size_t)uap->uaddr1, &timeout);
4175 if (error != 0)
4176 return (error);
4177 error = do_rw_rdlock(td, uap->obj, uap->val, &timeout);
4178 }
4179 return (error);
4180 }
4181
4182 static int
__umtx_op_rw_wrlock(struct thread * td,struct _umtx_op_args * uap,const struct umtx_copyops * ops)4183 __umtx_op_rw_wrlock(struct thread *td, struct _umtx_op_args *uap,
4184 const struct umtx_copyops *ops)
4185 {
4186 struct _umtx_time timeout;
4187 int error;
4188
4189 /* Allow a null timespec (wait forever). */
4190 if (uap->uaddr2 == NULL) {
4191 error = do_rw_wrlock(td, uap->obj, 0);
4192 } else {
4193 error = ops->copyin_umtx_time(uap->uaddr2,
4194 (size_t)uap->uaddr1, &timeout);
4195 if (error != 0)
4196 return (error);
4197
4198 error = do_rw_wrlock(td, uap->obj, &timeout);
4199 }
4200 return (error);
4201 }
4202
4203 static int
__umtx_op_rw_unlock(struct thread * td,struct _umtx_op_args * uap,const struct umtx_copyops * ops __unused)4204 __umtx_op_rw_unlock(struct thread *td, struct _umtx_op_args *uap,
4205 const struct umtx_copyops *ops __unused)
4206 {
4207
4208 return (do_rw_unlock(td, uap->obj));
4209 }
4210
4211 #if defined(COMPAT_FREEBSD9) || defined(COMPAT_FREEBSD10)
4212 static int
__umtx_op_sem_wait(struct thread * td,struct _umtx_op_args * uap,const struct umtx_copyops * ops)4213 __umtx_op_sem_wait(struct thread *td, struct _umtx_op_args *uap,
4214 const struct umtx_copyops *ops)
4215 {
4216 struct _umtx_time *tm_p, timeout;
4217 int error;
4218
4219 /* Allow a null timespec (wait forever). */
4220 if (uap->uaddr2 == NULL)
4221 tm_p = NULL;
4222 else {
4223 error = ops->copyin_umtx_time(
4224 uap->uaddr2, (size_t)uap->uaddr1, &timeout);
4225 if (error != 0)
4226 return (error);
4227 tm_p = &timeout;
4228 }
4229 return (do_sem_wait(td, uap->obj, tm_p));
4230 }
4231
4232 static int
__umtx_op_sem_wake(struct thread * td,struct _umtx_op_args * uap,const struct umtx_copyops * ops __unused)4233 __umtx_op_sem_wake(struct thread *td, struct _umtx_op_args *uap,
4234 const struct umtx_copyops *ops __unused)
4235 {
4236
4237 return (do_sem_wake(td, uap->obj));
4238 }
4239 #endif
4240
4241 static int
__umtx_op_wake2_umutex(struct thread * td,struct _umtx_op_args * uap,const struct umtx_copyops * ops __unused)4242 __umtx_op_wake2_umutex(struct thread *td, struct _umtx_op_args *uap,
4243 const struct umtx_copyops *ops __unused)
4244 {
4245
4246 return (do_wake2_umutex(td, uap->obj, uap->val));
4247 }
4248
4249 static int
__umtx_op_sem2_wait(struct thread * td,struct _umtx_op_args * uap,const struct umtx_copyops * ops)4250 __umtx_op_sem2_wait(struct thread *td, struct _umtx_op_args *uap,
4251 const struct umtx_copyops *ops)
4252 {
4253 struct _umtx_time *tm_p, timeout;
4254 size_t uasize;
4255 int error;
4256
4257 /* Allow a null timespec (wait forever). */
4258 if (uap->uaddr2 == NULL) {
4259 uasize = 0;
4260 tm_p = NULL;
4261 } else {
4262 uasize = (size_t)uap->uaddr1;
4263 error = ops->copyin_umtx_time(uap->uaddr2, uasize, &timeout);
4264 if (error != 0)
4265 return (error);
4266 tm_p = &timeout;
4267 }
4268 error = do_sem2_wait(td, uap->obj, tm_p);
4269 if (error == EINTR && uap->uaddr2 != NULL &&
4270 (timeout._flags & UMTX_ABSTIME) == 0 &&
4271 uasize >= ops->umtx_time_sz + ops->timespec_sz) {
4272 error = ops->copyout_timeout(
4273 (void *)((uintptr_t)uap->uaddr2 + ops->umtx_time_sz),
4274 uasize - ops->umtx_time_sz, &timeout._timeout);
4275 if (error == 0) {
4276 error = EINTR;
4277 }
4278 }
4279
4280 return (error);
4281 }
4282
4283 static int
__umtx_op_sem2_wake(struct thread * td,struct _umtx_op_args * uap,const struct umtx_copyops * ops __unused)4284 __umtx_op_sem2_wake(struct thread *td, struct _umtx_op_args *uap,
4285 const struct umtx_copyops *ops __unused)
4286 {
4287
4288 return (do_sem2_wake(td, uap->obj));
4289 }
4290
4291 #define USHM_OBJ_UMTX(o) \
4292 ((struct umtx_shm_obj_list *)(&(o)->umtx_data))
4293
4294 #define USHMF_LINKED 0x0001
4295 struct umtx_shm_reg {
4296 TAILQ_ENTRY(umtx_shm_reg) ushm_reg_link;
4297 LIST_ENTRY(umtx_shm_reg) ushm_obj_link;
4298 struct umtx_key ushm_key;
4299 struct ucred *ushm_cred;
4300 struct shmfd *ushm_obj;
4301 u_int ushm_refcnt;
4302 u_int ushm_flags;
4303 };
4304
4305 LIST_HEAD(umtx_shm_obj_list, umtx_shm_reg);
4306 TAILQ_HEAD(umtx_shm_reg_head, umtx_shm_reg);
4307
4308 static uma_zone_t umtx_shm_reg_zone;
4309 static struct umtx_shm_reg_head umtx_shm_registry[UMTX_CHAINS];
4310 static struct mtx umtx_shm_lock;
4311 static struct umtx_shm_reg_head umtx_shm_reg_delfree =
4312 TAILQ_HEAD_INITIALIZER(umtx_shm_reg_delfree);
4313
4314 static void umtx_shm_free_reg(struct umtx_shm_reg *reg);
4315
4316 static void
umtx_shm_reg_delfree_tq(void * context __unused,int pending __unused)4317 umtx_shm_reg_delfree_tq(void *context __unused, int pending __unused)
4318 {
4319 struct umtx_shm_reg_head d;
4320 struct umtx_shm_reg *reg, *reg1;
4321
4322 TAILQ_INIT(&d);
4323 mtx_lock(&umtx_shm_lock);
4324 TAILQ_CONCAT(&d, &umtx_shm_reg_delfree, ushm_reg_link);
4325 mtx_unlock(&umtx_shm_lock);
4326 TAILQ_FOREACH_SAFE(reg, &d, ushm_reg_link, reg1) {
4327 TAILQ_REMOVE(&d, reg, ushm_reg_link);
4328 umtx_shm_free_reg(reg);
4329 }
4330 }
4331
4332 static struct task umtx_shm_reg_delfree_task =
4333 TASK_INITIALIZER(0, umtx_shm_reg_delfree_tq, NULL);
4334
4335 /*
4336 * Returns 0 if a SHM with the passed key is found in the registry, in which
4337 * case it is returned through 'oreg'. Otherwise, returns an error among ESRCH
4338 * (no corresponding SHM; ESRCH was chosen for compatibility, ENOENT would have
4339 * been preferable) or EOVERFLOW (there is a corresponding SHM, but reference
4340 * count would overflow, so can't return it), in which case '*oreg' is left
4341 * unchanged.
4342 */
4343 static int
umtx_shm_find_reg_locked(const struct umtx_key * key,struct umtx_shm_reg ** const oreg)4344 umtx_shm_find_reg_locked(const struct umtx_key *key,
4345 struct umtx_shm_reg **const oreg)
4346 {
4347 struct umtx_shm_reg *reg;
4348 struct umtx_shm_reg_head *reg_head;
4349
4350 KASSERT(key->shared, ("umtx_p_find_rg: private key"));
4351 mtx_assert(&umtx_shm_lock, MA_OWNED);
4352 reg_head = &umtx_shm_registry[key->hash];
4353 TAILQ_FOREACH(reg, reg_head, ushm_reg_link) {
4354 KASSERT(reg->ushm_key.shared,
4355 ("non-shared key on reg %p %d", reg, reg->ushm_key.shared));
4356 if (reg->ushm_key.info.shared.object ==
4357 key->info.shared.object &&
4358 reg->ushm_key.info.shared.offset ==
4359 key->info.shared.offset) {
4360 KASSERT(reg->ushm_key.type == TYPE_SHM, ("TYPE_USHM"));
4361 KASSERT(reg->ushm_refcnt != 0,
4362 ("reg %p refcnt 0 onlist", reg));
4363 KASSERT((reg->ushm_flags & USHMF_LINKED) != 0,
4364 ("reg %p not linked", reg));
4365 /*
4366 * Don't let overflow happen, just deny a new reference
4367 * (this is additional protection against some reference
4368 * count leak, which is known not to be the case at the
4369 * time of this writing).
4370 */
4371 if (__predict_false(reg->ushm_refcnt == UINT_MAX))
4372 return (EOVERFLOW);
4373 reg->ushm_refcnt++;
4374 *oreg = reg;
4375 return (0);
4376 }
4377 }
4378 return (ESRCH);
4379 }
4380
4381 /*
4382 * Calls umtx_shm_find_reg_unlocked() under the 'umtx_shm_lock'.
4383 */
4384 static int
umtx_shm_find_reg(const struct umtx_key * key,struct umtx_shm_reg ** const oreg)4385 umtx_shm_find_reg(const struct umtx_key *key, struct umtx_shm_reg **const oreg)
4386 {
4387 int error;
4388
4389 mtx_lock(&umtx_shm_lock);
4390 error = umtx_shm_find_reg_locked(key, oreg);
4391 mtx_unlock(&umtx_shm_lock);
4392 return (error);
4393 }
4394
4395 static void
umtx_shm_free_reg(struct umtx_shm_reg * reg)4396 umtx_shm_free_reg(struct umtx_shm_reg *reg)
4397 {
4398
4399 chgumtxcnt(reg->ushm_cred->cr_ruidinfo, -1, 0);
4400 crfree(reg->ushm_cred);
4401 shm_drop(reg->ushm_obj);
4402 uma_zfree(umtx_shm_reg_zone, reg);
4403 }
4404
4405 static bool
umtx_shm_unref_reg_locked(struct umtx_shm_reg * reg,bool linked_ref)4406 umtx_shm_unref_reg_locked(struct umtx_shm_reg *reg, bool linked_ref)
4407 {
4408 mtx_assert(&umtx_shm_lock, MA_OWNED);
4409 KASSERT(reg->ushm_refcnt != 0, ("ushm_reg %p refcnt 0", reg));
4410
4411 if (linked_ref) {
4412 if ((reg->ushm_flags & USHMF_LINKED) == 0)
4413 /*
4414 * The reference tied to USHMF_LINKED has already been
4415 * released concurrently.
4416 */
4417 return (false);
4418
4419 TAILQ_REMOVE(&umtx_shm_registry[reg->ushm_key.hash], reg,
4420 ushm_reg_link);
4421 LIST_REMOVE(reg, ushm_obj_link);
4422 reg->ushm_flags &= ~USHMF_LINKED;
4423 }
4424
4425 reg->ushm_refcnt--;
4426 return (reg->ushm_refcnt == 0);
4427 }
4428
4429 static void
umtx_shm_unref_reg(struct umtx_shm_reg * reg,bool linked_ref)4430 umtx_shm_unref_reg(struct umtx_shm_reg *reg, bool linked_ref)
4431 {
4432 vm_object_t object;
4433 bool dofree;
4434
4435 if (linked_ref) {
4436 /*
4437 * Note: This may be executed multiple times on the same
4438 * shared-memory VM object in presence of concurrent callers
4439 * because 'umtx_shm_lock' is not held all along in umtx_shm()
4440 * and here.
4441 */
4442 object = reg->ushm_obj->shm_object;
4443 VM_OBJECT_WLOCK(object);
4444 vm_object_set_flag(object, OBJ_UMTXDEAD);
4445 VM_OBJECT_WUNLOCK(object);
4446 }
4447 mtx_lock(&umtx_shm_lock);
4448 dofree = umtx_shm_unref_reg_locked(reg, linked_ref);
4449 mtx_unlock(&umtx_shm_lock);
4450 if (dofree)
4451 umtx_shm_free_reg(reg);
4452 }
4453
4454 void
umtx_shm_object_init(vm_object_t object)4455 umtx_shm_object_init(vm_object_t object)
4456 {
4457
4458 LIST_INIT(USHM_OBJ_UMTX(object));
4459 }
4460
4461 void
umtx_shm_object_terminated(vm_object_t object)4462 umtx_shm_object_terminated(vm_object_t object)
4463 {
4464 struct umtx_shm_reg *reg, *reg1;
4465 bool dofree;
4466
4467 if (LIST_EMPTY(USHM_OBJ_UMTX(object)))
4468 return;
4469
4470 dofree = false;
4471 mtx_lock(&umtx_shm_lock);
4472 LIST_FOREACH_SAFE(reg, USHM_OBJ_UMTX(object), ushm_obj_link, reg1) {
4473 if (umtx_shm_unref_reg_locked(reg, true)) {
4474 TAILQ_INSERT_TAIL(&umtx_shm_reg_delfree, reg,
4475 ushm_reg_link);
4476 dofree = true;
4477 }
4478 }
4479 mtx_unlock(&umtx_shm_lock);
4480 if (dofree)
4481 taskqueue_enqueue(taskqueue_thread, &umtx_shm_reg_delfree_task);
4482 }
4483
4484 static int
umtx_shm_create_reg(struct thread * td,const struct umtx_key * key,struct umtx_shm_reg ** res)4485 umtx_shm_create_reg(struct thread *td, const struct umtx_key *key,
4486 struct umtx_shm_reg **res)
4487 {
4488 struct umtx_shm_reg *reg, *reg1;
4489 struct ucred *cred;
4490 int error;
4491
4492 error = umtx_shm_find_reg(key, res);
4493 if (error != ESRCH) {
4494 /*
4495 * Either no error occured, and '*res' was filled, or EOVERFLOW
4496 * was returned, indicating a reference count limit, and we
4497 * won't create a duplicate registration. In both cases, we are
4498 * done.
4499 */
4500 return (error);
4501 }
4502 /* No entry, we will create one. */
4503
4504 cred = td->td_ucred;
4505 if (!chgumtxcnt(cred->cr_ruidinfo, 1, lim_cur(td, RLIMIT_UMTXP)))
4506 return (ENOMEM);
4507 reg = uma_zalloc(umtx_shm_reg_zone, M_WAITOK | M_ZERO);
4508 bcopy(key, ®->ushm_key, sizeof(*key));
4509 reg->ushm_obj = shm_alloc(td->td_ucred, O_RDWR, false);
4510 reg->ushm_cred = crhold(cred);
4511 error = shm_dotruncate(reg->ushm_obj, PAGE_SIZE);
4512 if (error != 0) {
4513 umtx_shm_free_reg(reg);
4514 return (error);
4515 }
4516 mtx_lock(&umtx_shm_lock);
4517 /* Re-lookup as 'umtx_shm_lock' has been temporarily released. */
4518 error = umtx_shm_find_reg_locked(key, ®1);
4519 switch (error) {
4520 case 0:
4521 mtx_unlock(&umtx_shm_lock);
4522 umtx_shm_free_reg(reg);
4523 *res = reg1;
4524 return (0);
4525 case ESRCH:
4526 break;
4527 default:
4528 mtx_unlock(&umtx_shm_lock);
4529 umtx_shm_free_reg(reg);
4530 return (error);
4531 }
4532 TAILQ_INSERT_TAIL(&umtx_shm_registry[key->hash], reg, ushm_reg_link);
4533 LIST_INSERT_HEAD(USHM_OBJ_UMTX(key->info.shared.object), reg,
4534 ushm_obj_link);
4535 reg->ushm_flags = USHMF_LINKED;
4536 /*
4537 * This is one reference for the registry and the list of shared
4538 * mutexes referenced by the VM object containing the lock pointer, and
4539 * another for the caller, which it will free after use. So, one of
4540 * these is tied to the presence of USHMF_LINKED.
4541 */
4542 reg->ushm_refcnt = 2;
4543 mtx_unlock(&umtx_shm_lock);
4544 *res = reg;
4545 return (0);
4546 }
4547
4548 static int
umtx_shm_alive(struct thread * td,void * addr)4549 umtx_shm_alive(struct thread *td, void *addr)
4550 {
4551 vm_map_t map;
4552 vm_map_entry_t entry;
4553 vm_object_t object;
4554 vm_pindex_t pindex;
4555 vm_prot_t prot;
4556 int res, ret;
4557 boolean_t wired;
4558
4559 map = &td->td_proc->p_vmspace->vm_map;
4560 res = vm_map_lookup(&map, (uintptr_t)addr, VM_PROT_READ, &entry,
4561 &object, &pindex, &prot, &wired);
4562 if (res != KERN_SUCCESS)
4563 return (EFAULT);
4564 if (object == NULL)
4565 ret = EINVAL;
4566 else
4567 ret = (object->flags & OBJ_UMTXDEAD) != 0 ? ENOTTY : 0;
4568 vm_map_lookup_done(map, entry);
4569 return (ret);
4570 }
4571
4572 static void
umtx_shm_init(void)4573 umtx_shm_init(void)
4574 {
4575 int i;
4576
4577 umtx_shm_reg_zone = uma_zcreate("umtx_shm", sizeof(struct umtx_shm_reg),
4578 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
4579 mtx_init(&umtx_shm_lock, "umtxshm", NULL, MTX_DEF);
4580 for (i = 0; i < nitems(umtx_shm_registry); i++)
4581 TAILQ_INIT(&umtx_shm_registry[i]);
4582 }
4583
4584 static int
umtx_shm(struct thread * td,void * addr,u_int flags)4585 umtx_shm(struct thread *td, void *addr, u_int flags)
4586 {
4587 struct umtx_key key;
4588 struct umtx_shm_reg *reg;
4589 struct file *fp;
4590 int error, fd;
4591
4592 if (__bitcount(flags & (UMTX_SHM_CREAT | UMTX_SHM_LOOKUP |
4593 UMTX_SHM_DESTROY| UMTX_SHM_ALIVE)) != 1)
4594 return (EINVAL);
4595 if ((flags & UMTX_SHM_ALIVE) != 0)
4596 return (umtx_shm_alive(td, addr));
4597 error = umtx_key_get(addr, TYPE_SHM, PROCESS_SHARE, &key);
4598 if (error != 0)
4599 return (error);
4600 KASSERT(key.shared == 1, ("non-shared key"));
4601 error = (flags & UMTX_SHM_CREAT) != 0 ?
4602 umtx_shm_create_reg(td, &key, ®) :
4603 umtx_shm_find_reg(&key, ®);
4604 umtx_key_release(&key);
4605 if (error != 0)
4606 return (error);
4607 KASSERT(reg != NULL, ("no reg"));
4608 if ((flags & UMTX_SHM_DESTROY) != 0) {
4609 umtx_shm_unref_reg(reg, true);
4610 } else {
4611 #if 0
4612 #ifdef MAC
4613 error = mac_posixshm_check_open(td->td_ucred,
4614 reg->ushm_obj, FFLAGS(O_RDWR));
4615 if (error == 0)
4616 #endif
4617 error = shm_access(reg->ushm_obj, td->td_ucred,
4618 FFLAGS(O_RDWR));
4619 if (error == 0)
4620 #endif
4621 error = falloc_caps(td, &fp, &fd, O_CLOEXEC, NULL);
4622 if (error == 0) {
4623 shm_hold(reg->ushm_obj);
4624 finit(fp, FFLAGS(O_RDWR), DTYPE_SHM, reg->ushm_obj,
4625 &shm_ops);
4626 td->td_retval[0] = fd;
4627 fdrop(fp, td);
4628 }
4629 }
4630 umtx_shm_unref_reg(reg, false);
4631 return (error);
4632 }
4633
4634 static int
__umtx_op_shm(struct thread * td,struct _umtx_op_args * uap,const struct umtx_copyops * ops __unused)4635 __umtx_op_shm(struct thread *td, struct _umtx_op_args *uap,
4636 const struct umtx_copyops *ops __unused)
4637 {
4638
4639 return (umtx_shm(td, uap->uaddr1, uap->val));
4640 }
4641
4642 static int
__umtx_op_robust_lists(struct thread * td,struct _umtx_op_args * uap,const struct umtx_copyops * ops)4643 __umtx_op_robust_lists(struct thread *td, struct _umtx_op_args *uap,
4644 const struct umtx_copyops *ops)
4645 {
4646 struct umtx_robust_lists_params rb;
4647 int error;
4648
4649 if (ops->compat32) {
4650 if ((td->td_pflags2 & TDP2_COMPAT32RB) == 0 &&
4651 (td->td_rb_list != 0 || td->td_rbp_list != 0 ||
4652 td->td_rb_inact != 0))
4653 return (EBUSY);
4654 } else if ((td->td_pflags2 & TDP2_COMPAT32RB) != 0) {
4655 return (EBUSY);
4656 }
4657
4658 bzero(&rb, sizeof(rb));
4659 error = ops->copyin_robust_lists(uap->uaddr1, uap->val, &rb);
4660 if (error != 0)
4661 return (error);
4662
4663 if (ops->compat32)
4664 td->td_pflags2 |= TDP2_COMPAT32RB;
4665
4666 td->td_rb_list = rb.robust_list_offset;
4667 td->td_rbp_list = rb.robust_priv_list_offset;
4668 td->td_rb_inact = rb.robust_inact_offset;
4669 return (0);
4670 }
4671
4672 static int
__umtx_op_get_min_timeout(struct thread * td,struct _umtx_op_args * uap,const struct umtx_copyops * ops)4673 __umtx_op_get_min_timeout(struct thread *td, struct _umtx_op_args *uap,
4674 const struct umtx_copyops *ops)
4675 {
4676 long val;
4677 int error, val1;
4678
4679 val = sbttons(td->td_proc->p_umtx_min_timeout);
4680 if (ops->compat32) {
4681 val1 = (int)val;
4682 error = copyout(&val1, uap->uaddr1, sizeof(val1));
4683 } else {
4684 error = copyout(&val, uap->uaddr1, sizeof(val));
4685 }
4686 return (error);
4687 }
4688
4689 static int
__umtx_op_set_min_timeout(struct thread * td,struct _umtx_op_args * uap,const struct umtx_copyops * ops)4690 __umtx_op_set_min_timeout(struct thread *td, struct _umtx_op_args *uap,
4691 const struct umtx_copyops *ops)
4692 {
4693 if (uap->val < 0)
4694 return (EINVAL);
4695 td->td_proc->p_umtx_min_timeout = nstosbt(uap->val);
4696 return (0);
4697 }
4698
4699 #if defined(__i386__) || defined(__amd64__)
4700 /*
4701 * Provide the standard 32-bit definitions for x86, since native/compat32 use a
4702 * 32-bit time_t there. Other architectures just need the i386 definitions
4703 * along with their standard compat32.
4704 */
4705 struct timespecx32 {
4706 int64_t tv_sec;
4707 int32_t tv_nsec;
4708 };
4709
4710 struct umtx_timex32 {
4711 struct timespecx32 _timeout;
4712 uint32_t _flags;
4713 uint32_t _clockid;
4714 };
4715
4716 #ifndef __i386__
4717 #define timespeci386 timespec32
4718 #define umtx_timei386 umtx_time32
4719 #endif
4720 #else /* !__i386__ && !__amd64__ */
4721 /* 32-bit architectures can emulate i386, so define these almost everywhere. */
4722 struct timespeci386 {
4723 int32_t tv_sec;
4724 int32_t tv_nsec;
4725 };
4726
4727 struct umtx_timei386 {
4728 struct timespeci386 _timeout;
4729 uint32_t _flags;
4730 uint32_t _clockid;
4731 };
4732
4733 #if defined(__LP64__)
4734 #define timespecx32 timespec32
4735 #define umtx_timex32 umtx_time32
4736 #endif
4737 #endif
4738
4739 static int
umtx_copyin_robust_lists32(const void * uaddr,size_t size,struct umtx_robust_lists_params * rbp)4740 umtx_copyin_robust_lists32(const void *uaddr, size_t size,
4741 struct umtx_robust_lists_params *rbp)
4742 {
4743 struct umtx_robust_lists_params_compat32 rb32;
4744 int error;
4745
4746 if (size > sizeof(rb32))
4747 return (EINVAL);
4748 bzero(&rb32, sizeof(rb32));
4749 error = copyin(uaddr, &rb32, size);
4750 if (error != 0)
4751 return (error);
4752 CP(rb32, *rbp, robust_list_offset);
4753 CP(rb32, *rbp, robust_priv_list_offset);
4754 CP(rb32, *rbp, robust_inact_offset);
4755 return (0);
4756 }
4757
4758 #ifndef __i386__
4759 static inline int
umtx_copyin_timeouti386(const void * uaddr,struct timespec * tsp)4760 umtx_copyin_timeouti386(const void *uaddr, struct timespec *tsp)
4761 {
4762 struct timespeci386 ts32;
4763 int error;
4764
4765 error = copyin(uaddr, &ts32, sizeof(ts32));
4766 if (error == 0) {
4767 if (!timespecvalid_interval(&ts32))
4768 error = EINVAL;
4769 else {
4770 CP(ts32, *tsp, tv_sec);
4771 CP(ts32, *tsp, tv_nsec);
4772 }
4773 }
4774 return (error);
4775 }
4776
4777 static inline int
umtx_copyin_umtx_timei386(const void * uaddr,size_t size,struct _umtx_time * tp)4778 umtx_copyin_umtx_timei386(const void *uaddr, size_t size, struct _umtx_time *tp)
4779 {
4780 struct umtx_timei386 t32;
4781 int error;
4782
4783 t32._clockid = CLOCK_REALTIME;
4784 t32._flags = 0;
4785 if (size <= sizeof(t32._timeout))
4786 error = copyin(uaddr, &t32._timeout, sizeof(t32._timeout));
4787 else
4788 error = copyin(uaddr, &t32, sizeof(t32));
4789 if (error != 0)
4790 return (error);
4791 if (!timespecvalid_interval(&t32._timeout))
4792 return (EINVAL);
4793 TS_CP(t32, *tp, _timeout);
4794 CP(t32, *tp, _flags);
4795 CP(t32, *tp, _clockid);
4796 return (0);
4797 }
4798
4799 static int
umtx_copyout_timeouti386(void * uaddr,size_t sz,struct timespec * tsp)4800 umtx_copyout_timeouti386(void *uaddr, size_t sz, struct timespec *tsp)
4801 {
4802 struct timespeci386 remain32 = {
4803 .tv_sec = tsp->tv_sec,
4804 .tv_nsec = tsp->tv_nsec,
4805 };
4806
4807 /*
4808 * Should be guaranteed by the caller, sz == uaddr1 - sizeof(_umtx_time)
4809 * and we're only called if sz >= sizeof(timespec) as supplied in the
4810 * copyops.
4811 */
4812 KASSERT(sz >= sizeof(remain32),
4813 ("umtx_copyops specifies incorrect sizes"));
4814
4815 return (copyout(&remain32, uaddr, sizeof(remain32)));
4816 }
4817 #endif /* !__i386__ */
4818
4819 #if defined(__i386__) || defined(__LP64__)
4820 static inline int
umtx_copyin_timeoutx32(const void * uaddr,struct timespec * tsp)4821 umtx_copyin_timeoutx32(const void *uaddr, struct timespec *tsp)
4822 {
4823 struct timespecx32 ts32;
4824 int error;
4825
4826 error = copyin(uaddr, &ts32, sizeof(ts32));
4827 if (error == 0) {
4828 if (!timespecvalid_interval(&ts32))
4829 error = EINVAL;
4830 else {
4831 CP(ts32, *tsp, tv_sec);
4832 CP(ts32, *tsp, tv_nsec);
4833 }
4834 }
4835 return (error);
4836 }
4837
4838 static inline int
umtx_copyin_umtx_timex32(const void * uaddr,size_t size,struct _umtx_time * tp)4839 umtx_copyin_umtx_timex32(const void *uaddr, size_t size, struct _umtx_time *tp)
4840 {
4841 struct umtx_timex32 t32;
4842 int error;
4843
4844 t32._clockid = CLOCK_REALTIME;
4845 t32._flags = 0;
4846 if (size <= sizeof(t32._timeout))
4847 error = copyin(uaddr, &t32._timeout, sizeof(t32._timeout));
4848 else
4849 error = copyin(uaddr, &t32, sizeof(t32));
4850 if (error != 0)
4851 return (error);
4852 if (!timespecvalid_interval(&t32._timeout))
4853 return (EINVAL);
4854 TS_CP(t32, *tp, _timeout);
4855 CP(t32, *tp, _flags);
4856 CP(t32, *tp, _clockid);
4857 return (0);
4858 }
4859
4860 static int
umtx_copyout_timeoutx32(void * uaddr,size_t sz,struct timespec * tsp)4861 umtx_copyout_timeoutx32(void *uaddr, size_t sz, struct timespec *tsp)
4862 {
4863 struct timespecx32 remain32 = {
4864 .tv_sec = tsp->tv_sec,
4865 .tv_nsec = tsp->tv_nsec,
4866 };
4867
4868 /*
4869 * Should be guaranteed by the caller, sz == uaddr1 - sizeof(_umtx_time)
4870 * and we're only called if sz >= sizeof(timespec) as supplied in the
4871 * copyops.
4872 */
4873 KASSERT(sz >= sizeof(remain32),
4874 ("umtx_copyops specifies incorrect sizes"));
4875
4876 return (copyout(&remain32, uaddr, sizeof(remain32)));
4877 }
4878 #endif /* __i386__ || __LP64__ */
4879
4880 typedef int (*_umtx_op_func)(struct thread *td, struct _umtx_op_args *uap,
4881 const struct umtx_copyops *umtx_ops);
4882
4883 static const _umtx_op_func op_table[] = {
4884 #ifdef COMPAT_FREEBSD10
4885 [UMTX_OP_LOCK] = __umtx_op_lock_umtx,
4886 [UMTX_OP_UNLOCK] = __umtx_op_unlock_umtx,
4887 #else
4888 [UMTX_OP_LOCK] = __umtx_op_unimpl,
4889 [UMTX_OP_UNLOCK] = __umtx_op_unimpl,
4890 #endif
4891 [UMTX_OP_WAIT] = __umtx_op_wait,
4892 [UMTX_OP_WAKE] = __umtx_op_wake,
4893 [UMTX_OP_MUTEX_TRYLOCK] = __umtx_op_trylock_umutex,
4894 [UMTX_OP_MUTEX_LOCK] = __umtx_op_lock_umutex,
4895 [UMTX_OP_MUTEX_UNLOCK] = __umtx_op_unlock_umutex,
4896 [UMTX_OP_SET_CEILING] = __umtx_op_set_ceiling,
4897 [UMTX_OP_CV_WAIT] = __umtx_op_cv_wait,
4898 [UMTX_OP_CV_SIGNAL] = __umtx_op_cv_signal,
4899 [UMTX_OP_CV_BROADCAST] = __umtx_op_cv_broadcast,
4900 [UMTX_OP_WAIT_UINT] = __umtx_op_wait_uint,
4901 [UMTX_OP_RW_RDLOCK] = __umtx_op_rw_rdlock,
4902 [UMTX_OP_RW_WRLOCK] = __umtx_op_rw_wrlock,
4903 [UMTX_OP_RW_UNLOCK] = __umtx_op_rw_unlock,
4904 [UMTX_OP_WAIT_UINT_PRIVATE] = __umtx_op_wait_uint_private,
4905 [UMTX_OP_WAKE_PRIVATE] = __umtx_op_wake_private,
4906 [UMTX_OP_MUTEX_WAIT] = __umtx_op_wait_umutex,
4907 [UMTX_OP_MUTEX_WAKE] = __umtx_op_wake_umutex,
4908 #if defined(COMPAT_FREEBSD9) || defined(COMPAT_FREEBSD10)
4909 [UMTX_OP_SEM_WAIT] = __umtx_op_sem_wait,
4910 [UMTX_OP_SEM_WAKE] = __umtx_op_sem_wake,
4911 #else
4912 [UMTX_OP_SEM_WAIT] = __umtx_op_unimpl,
4913 [UMTX_OP_SEM_WAKE] = __umtx_op_unimpl,
4914 #endif
4915 [UMTX_OP_NWAKE_PRIVATE] = __umtx_op_nwake_private,
4916 [UMTX_OP_MUTEX_WAKE2] = __umtx_op_wake2_umutex,
4917 [UMTX_OP_SEM2_WAIT] = __umtx_op_sem2_wait,
4918 [UMTX_OP_SEM2_WAKE] = __umtx_op_sem2_wake,
4919 [UMTX_OP_SHM] = __umtx_op_shm,
4920 [UMTX_OP_ROBUST_LISTS] = __umtx_op_robust_lists,
4921 [UMTX_OP_GET_MIN_TIMEOUT] = __umtx_op_get_min_timeout,
4922 [UMTX_OP_SET_MIN_TIMEOUT] = __umtx_op_set_min_timeout,
4923 };
4924
4925 static const struct umtx_copyops umtx_native_ops = {
4926 .copyin_timeout = umtx_copyin_timeout,
4927 .copyin_umtx_time = umtx_copyin_umtx_time,
4928 .copyin_robust_lists = umtx_copyin_robust_lists,
4929 .copyout_timeout = umtx_copyout_timeout,
4930 .timespec_sz = sizeof(struct timespec),
4931 .umtx_time_sz = sizeof(struct _umtx_time),
4932 };
4933
4934 #ifndef __i386__
4935 static const struct umtx_copyops umtx_native_opsi386 = {
4936 .copyin_timeout = umtx_copyin_timeouti386,
4937 .copyin_umtx_time = umtx_copyin_umtx_timei386,
4938 .copyin_robust_lists = umtx_copyin_robust_lists32,
4939 .copyout_timeout = umtx_copyout_timeouti386,
4940 .timespec_sz = sizeof(struct timespeci386),
4941 .umtx_time_sz = sizeof(struct umtx_timei386),
4942 .compat32 = true,
4943 };
4944 #endif
4945
4946 #if defined(__i386__) || defined(__LP64__)
4947 /* i386 can emulate other 32-bit archs, too! */
4948 static const struct umtx_copyops umtx_native_opsx32 = {
4949 .copyin_timeout = umtx_copyin_timeoutx32,
4950 .copyin_umtx_time = umtx_copyin_umtx_timex32,
4951 .copyin_robust_lists = umtx_copyin_robust_lists32,
4952 .copyout_timeout = umtx_copyout_timeoutx32,
4953 .timespec_sz = sizeof(struct timespecx32),
4954 .umtx_time_sz = sizeof(struct umtx_timex32),
4955 .compat32 = true,
4956 };
4957
4958 #ifdef COMPAT_FREEBSD32
4959 #ifdef __amd64__
4960 #define umtx_native_ops32 umtx_native_opsi386
4961 #else
4962 #define umtx_native_ops32 umtx_native_opsx32
4963 #endif
4964 #endif /* COMPAT_FREEBSD32 */
4965 #endif /* __i386__ || __LP64__ */
4966
4967 #define UMTX_OP__FLAGS (UMTX_OP__32BIT | UMTX_OP__I386)
4968
4969 static int
kern__umtx_op(struct thread * td,void * obj,int op,unsigned long val,void * uaddr1,void * uaddr2,const struct umtx_copyops * ops)4970 kern__umtx_op(struct thread *td, void *obj, int op, unsigned long val,
4971 void *uaddr1, void *uaddr2, const struct umtx_copyops *ops)
4972 {
4973 struct _umtx_op_args uap = {
4974 .obj = obj,
4975 .op = op & ~UMTX_OP__FLAGS,
4976 .val = val,
4977 .uaddr1 = uaddr1,
4978 .uaddr2 = uaddr2
4979 };
4980
4981 if ((uap.op >= nitems(op_table)))
4982 return (EINVAL);
4983 return ((*op_table[uap.op])(td, &uap, ops));
4984 }
4985
4986 int
sys__umtx_op(struct thread * td,struct _umtx_op_args * uap)4987 sys__umtx_op(struct thread *td, struct _umtx_op_args *uap)
4988 {
4989 static const struct umtx_copyops *umtx_ops;
4990
4991 umtx_ops = &umtx_native_ops;
4992 #ifdef __LP64__
4993 if ((uap->op & (UMTX_OP__32BIT | UMTX_OP__I386)) != 0) {
4994 if ((uap->op & UMTX_OP__I386) != 0)
4995 umtx_ops = &umtx_native_opsi386;
4996 else
4997 umtx_ops = &umtx_native_opsx32;
4998 }
4999 #elif !defined(__i386__)
5000 /* We consider UMTX_OP__32BIT a nop on !i386 ILP32. */
5001 if ((uap->op & UMTX_OP__I386) != 0)
5002 umtx_ops = &umtx_native_opsi386;
5003 #else
5004 /* Likewise, UMTX_OP__I386 is a nop on i386. */
5005 if ((uap->op & UMTX_OP__32BIT) != 0)
5006 umtx_ops = &umtx_native_opsx32;
5007 #endif
5008 return (kern__umtx_op(td, uap->obj, uap->op, uap->val, uap->uaddr1,
5009 uap->uaddr2, umtx_ops));
5010 }
5011
5012 #ifdef COMPAT_FREEBSD32
5013 #ifdef COMPAT_FREEBSD10
5014 int
freebsd10_freebsd32__umtx_lock(struct thread * td,struct freebsd10_freebsd32__umtx_lock_args * uap)5015 freebsd10_freebsd32__umtx_lock(struct thread *td,
5016 struct freebsd10_freebsd32__umtx_lock_args *uap)
5017 {
5018 return (do_lock_umtx32(td, (uint32_t *)uap->umtx, td->td_tid, NULL));
5019 }
5020
5021 int
freebsd10_freebsd32__umtx_unlock(struct thread * td,struct freebsd10_freebsd32__umtx_unlock_args * uap)5022 freebsd10_freebsd32__umtx_unlock(struct thread *td,
5023 struct freebsd10_freebsd32__umtx_unlock_args *uap)
5024 {
5025 return (do_unlock_umtx32(td, (uint32_t *)uap->umtx, td->td_tid));
5026 }
5027 #endif /* COMPAT_FREEBSD10 */
5028
5029 int
freebsd32__umtx_op(struct thread * td,struct freebsd32__umtx_op_args * uap)5030 freebsd32__umtx_op(struct thread *td, struct freebsd32__umtx_op_args *uap)
5031 {
5032
5033 return (kern__umtx_op(td, uap->obj, uap->op, uap->val, uap->uaddr1,
5034 uap->uaddr2, &umtx_native_ops32));
5035 }
5036 #endif /* COMPAT_FREEBSD32 */
5037
5038 void
umtx_thread_init(struct thread * td)5039 umtx_thread_init(struct thread *td)
5040 {
5041
5042 td->td_umtxq = umtxq_alloc();
5043 td->td_umtxq->uq_thread = td;
5044 }
5045
5046 void
umtx_thread_fini(struct thread * td)5047 umtx_thread_fini(struct thread *td)
5048 {
5049
5050 umtxq_free(td->td_umtxq);
5051 }
5052
5053 /*
5054 * It will be called when new thread is created, e.g fork().
5055 */
5056 void
umtx_thread_alloc(struct thread * td)5057 umtx_thread_alloc(struct thread *td)
5058 {
5059 struct umtx_q *uq;
5060
5061 uq = td->td_umtxq;
5062 uq->uq_inherited_pri = PRI_MAX;
5063
5064 KASSERT(uq->uq_flags == 0, ("uq_flags != 0"));
5065 KASSERT(uq->uq_thread == td, ("uq_thread != td"));
5066 KASSERT(uq->uq_pi_blocked == NULL, ("uq_pi_blocked != NULL"));
5067 KASSERT(TAILQ_EMPTY(&uq->uq_pi_contested), ("uq_pi_contested is not empty"));
5068 }
5069
5070 /*
5071 * exec() hook.
5072 *
5073 * Clear robust lists for all process' threads, not delaying the
5074 * cleanup to thread exit, since the relevant address space is
5075 * destroyed right now.
5076 */
5077 void
umtx_exec(struct proc * p)5078 umtx_exec(struct proc *p)
5079 {
5080 struct thread *td;
5081
5082 KASSERT(p == curproc, ("need curproc"));
5083 KASSERT((p->p_flag & P_HADTHREADS) == 0 ||
5084 (p->p_flag & P_STOPPED_SINGLE) != 0,
5085 ("curproc must be single-threaded"));
5086 /*
5087 * There is no need to lock the list as only this thread can be
5088 * running.
5089 */
5090 FOREACH_THREAD_IN_PROC(p, td) {
5091 KASSERT(td == curthread ||
5092 ((td->td_flags & TDF_BOUNDARY) != 0 && TD_IS_SUSPENDED(td)),
5093 ("running thread %p %p", p, td));
5094 umtx_thread_cleanup(td);
5095 td->td_rb_list = td->td_rbp_list = td->td_rb_inact = 0;
5096 }
5097
5098 p->p_umtx_min_timeout = 0;
5099 }
5100
5101 /*
5102 * thread exit hook.
5103 */
5104 void
umtx_thread_exit(struct thread * td)5105 umtx_thread_exit(struct thread *td)
5106 {
5107
5108 umtx_thread_cleanup(td);
5109 }
5110
5111 static int
umtx_read_uptr(struct thread * td,uintptr_t ptr,uintptr_t * res,bool compat32)5112 umtx_read_uptr(struct thread *td, uintptr_t ptr, uintptr_t *res, bool compat32)
5113 {
5114 u_long res1;
5115 uint32_t res32;
5116 int error;
5117
5118 if (compat32) {
5119 error = fueword32((void *)ptr, &res32);
5120 if (error == 0)
5121 res1 = res32;
5122 } else {
5123 error = fueword((void *)ptr, &res1);
5124 }
5125 if (error == 0)
5126 *res = res1;
5127 else
5128 error = EFAULT;
5129 return (error);
5130 }
5131
5132 static void
umtx_read_rb_list(struct thread * td,struct umutex * m,uintptr_t * rb_list,bool compat32)5133 umtx_read_rb_list(struct thread *td, struct umutex *m, uintptr_t *rb_list,
5134 bool compat32)
5135 {
5136 struct umutex32 m32;
5137
5138 if (compat32) {
5139 memcpy(&m32, m, sizeof(m32));
5140 *rb_list = m32.m_rb_lnk;
5141 } else {
5142 *rb_list = m->m_rb_lnk;
5143 }
5144 }
5145
5146 static int
umtx_handle_rb(struct thread * td,uintptr_t rbp,uintptr_t * rb_list,bool inact,bool compat32)5147 umtx_handle_rb(struct thread *td, uintptr_t rbp, uintptr_t *rb_list, bool inact,
5148 bool compat32)
5149 {
5150 struct umutex m;
5151 int error;
5152
5153 KASSERT(td->td_proc == curproc, ("need current vmspace"));
5154 error = copyin((void *)rbp, &m, sizeof(m));
5155 if (error != 0)
5156 return (error);
5157 if (rb_list != NULL)
5158 umtx_read_rb_list(td, &m, rb_list, compat32);
5159 if ((m.m_flags & UMUTEX_ROBUST) == 0)
5160 return (EINVAL);
5161 if ((m.m_owner & ~UMUTEX_CONTESTED) != td->td_tid)
5162 /* inact is cleared after unlock, allow the inconsistency */
5163 return (inact ? 0 : EINVAL);
5164 return (do_unlock_umutex(td, (struct umutex *)rbp, true));
5165 }
5166
5167 static void
umtx_cleanup_rb_list(struct thread * td,uintptr_t rb_list,uintptr_t * rb_inact,const char * name,bool compat32)5168 umtx_cleanup_rb_list(struct thread *td, uintptr_t rb_list, uintptr_t *rb_inact,
5169 const char *name, bool compat32)
5170 {
5171 int error, i;
5172 uintptr_t rbp;
5173 bool inact;
5174
5175 if (rb_list == 0)
5176 return;
5177 error = umtx_read_uptr(td, rb_list, &rbp, compat32);
5178 for (i = 0; error == 0 && rbp != 0 && i < umtx_max_rb; i++) {
5179 if (rbp == *rb_inact) {
5180 inact = true;
5181 *rb_inact = 0;
5182 } else
5183 inact = false;
5184 error = umtx_handle_rb(td, rbp, &rbp, inact, compat32);
5185 }
5186 if (i == umtx_max_rb && umtx_verbose_rb) {
5187 uprintf("comm %s pid %d: reached umtx %smax rb %d\n",
5188 td->td_proc->p_comm, td->td_proc->p_pid, name, umtx_max_rb);
5189 }
5190 if (error != 0 && umtx_verbose_rb) {
5191 uprintf("comm %s pid %d: handling %srb error %d\n",
5192 td->td_proc->p_comm, td->td_proc->p_pid, name, error);
5193 }
5194 }
5195
5196 /*
5197 * Clean up umtx data.
5198 */
5199 static void
umtx_thread_cleanup(struct thread * td)5200 umtx_thread_cleanup(struct thread *td)
5201 {
5202 struct umtx_q *uq;
5203 struct umtx_pi *pi;
5204 uintptr_t rb_inact;
5205 bool compat32;
5206
5207 /*
5208 * Disown pi mutexes.
5209 */
5210 uq = td->td_umtxq;
5211 if (uq != NULL) {
5212 if (uq->uq_inherited_pri != PRI_MAX ||
5213 !TAILQ_EMPTY(&uq->uq_pi_contested)) {
5214 mtx_lock(&umtx_lock);
5215 uq->uq_inherited_pri = PRI_MAX;
5216 while ((pi = TAILQ_FIRST(&uq->uq_pi_contested)) != NULL) {
5217 pi->pi_owner = NULL;
5218 TAILQ_REMOVE(&uq->uq_pi_contested, pi, pi_link);
5219 }
5220 mtx_unlock(&umtx_lock);
5221 }
5222 sched_lend_user_prio_cond(td, PRI_MAX);
5223 }
5224
5225 compat32 = (td->td_pflags2 & TDP2_COMPAT32RB) != 0;
5226 td->td_pflags2 &= ~TDP2_COMPAT32RB;
5227
5228 if (td->td_rb_inact == 0 && td->td_rb_list == 0 && td->td_rbp_list == 0)
5229 return;
5230
5231 /*
5232 * Handle terminated robust mutexes. Must be done after
5233 * robust pi disown, otherwise unlock could see unowned
5234 * entries.
5235 */
5236 rb_inact = td->td_rb_inact;
5237 if (rb_inact != 0)
5238 (void)umtx_read_uptr(td, rb_inact, &rb_inact, compat32);
5239 umtx_cleanup_rb_list(td, td->td_rb_list, &rb_inact, "", compat32);
5240 umtx_cleanup_rb_list(td, td->td_rbp_list, &rb_inact, "priv ", compat32);
5241 if (rb_inact != 0)
5242 (void)umtx_handle_rb(td, rb_inact, NULL, true, compat32);
5243 }
5244